diff --git a/docs/COLQWEN_GUIDE.md b/docs/COLQWEN_GUIDE.md
new file mode 100644
index 0000000..42772f6
--- /dev/null
+++ b/docs/COLQWEN_GUIDE.md
@@ -0,0 +1,200 @@
+# ColQwen Integration Guide
+
+Easy-to-use multimodal PDF retrieval with ColQwen2/ColPali models.
+
+## Quick Start
+
+> **🍎 Mac Users**: ColQwen is optimized for Apple Silicon with MPS acceleration for faster inference!
+
+### 1. Install Dependencies
+```bash
+uv pip install colpali_engine pdf2image pillow matplotlib qwen_vl_utils einops seaborn
+brew install poppler  # macOS only, for PDF processing
+```
+
+### 2. Basic Usage
+```bash
+# Build index from PDFs
+python -m apps.colqwen_rag build --pdfs ./my_papers/ --index research_papers
+
+# Search with text queries
+python -m apps.colqwen_rag search research_papers "How does attention mechanism work?"
+
+# Interactive Q&A
+python -m apps.colqwen_rag ask research_papers --interactive
+```
+
+## Commands
+
+### Build Index
+```bash
+python -m apps.colqwen_rag build \
+  --pdfs ./pdf_directory/ \
+  --index my_index \
+  --model colqwen2 \
+  --pages-dir ./page_images/  # Optional: save page images
+```
+
+**Options:**
+- `--pdfs`: Directory containing PDF files (or single PDF path)
+- `--index`: Name for the index (required)
+- `--model`: `colqwen2` (default) or `colpali`
+- `--pages-dir`: Directory to save page images (optional)
+
+### Search Index
+```bash
+python -m apps.colqwen_rag search my_index "your question here" --top-k 5
+```
+
+**Options:**
+- `--top-k`: Number of results to return (default: 5)
+- `--model`: Model used for search (should match build model)
+
+### Interactive Q&A
+```bash
+python -m apps.colqwen_rag ask my_index --interactive
+```
+
+**Commands in interactive mode:**
+- Type your questions naturally
+- `help`: Show available commands
+- `quit`/`exit`/`q`: Exit interactive mode
+
+## 🧪 Test & Reproduce Results
+
+Run the reproduction test for issue #119:
+```bash
+python test_colqwen_reproduction.py
+```
+
+This will:
+1. ✅ Check dependencies
+2. 📥 Download sample PDF (Attention Is All You Need paper)
+3. 🏗️ Build test index
+4. 🔍 Run sample queries
+5. 📊 Show how to generate similarity maps
+
+## 🎨 Advanced: Similarity Maps
+
+For visual similarity analysis, use the existing advanced script:
+```bash
+cd apps/multimodal/vision-based-pdf-multi-vector/
+python multi-vector-leann-similarity-map.py
+```
+
+Edit the script to customize:
+- `QUERY`: Your question
+- `MODEL`: "colqwen2" or "colpali"
+- `USE_HF_DATASET`: Use HuggingFace dataset or local PDFs
+- `SIMILARITY_MAP`: Generate heatmaps
+- `ANSWER`: Enable Qwen-VL answer generation
+
+## 🔧 How It Works
+
+### ColQwen2 vs ColPali
+- **ColQwen2** (`vidore/colqwen2-v1.0`): Latest vision-language model
+- **ColPali** (`vidore/colpali-v1.2`): Proven multimodal retriever
+
+### Architecture
+1. **PDF → Images**: Convert PDF pages to images (150 DPI)
+2. **Vision Encoding**: Process images with ColQwen2/ColPali
+3. **Multi-Vector Index**: Build LEANN HNSW index with multiple embeddings per page
+4. **Query Processing**: Encode text queries with same model
+5. **Similarity Search**: Find most relevant pages/regions
+6. **Visual Maps**: Generate attention heatmaps (optional)
+
+### Device Support
+- **CUDA**: Best performance with GPU acceleration
+- **MPS**: Apple Silicon Mac support
+- **CPU**: Fallback for any system (slower)
+
+Auto-detection: CUDA > MPS > CPU
+
+## 📊 Performance Tips
+
+### For Best Performance:
+```bash
+# Use ColQwen2 for latest features
+--model colqwen2
+
+# Save page images for reuse
+--pages-dir ./cached_pages/
+
+# Adjust batch size based on GPU memory
+# (automatically handled)
+```
+
+### For Large Document Sets:
+- Process PDFs in batches
+- Use SSD storage for index files
+- Consider using CUDA if available
+
+## 🔗 Related Resources
+
+- **Fast-PLAID**: https://github.com/lightonai/fast-plaid
+- **Pylate**: https://github.com/lightonai/pylate
+- **ColBERT**: https://github.com/stanford-futuredata/ColBERT
+- **ColPali Paper**: Vision-Language Models for Document Retrieval
+- **Issue #119**: https://github.com/yichuan-w/LEANN/issues/119
+
+## 🐛 Troubleshooting
+
+### PDF Conversion Issues (macOS)
+```bash
+# Install poppler
+brew install poppler
+which pdfinfo && pdfinfo -v
+```
+
+### Memory Issues
+- Reduce batch size (automatically handled)
+- Use CPU instead of GPU: `export CUDA_VISIBLE_DEVICES=""`
+- Process fewer PDFs at once
+
+### Model Download Issues
+- Ensure internet connection for first run
+- Models are cached after first download
+- Use HuggingFace mirrors if needed
+
+### Import Errors
+```bash
+# Ensure all dependencies installed
+uv pip install colpali_engine pdf2image pillow matplotlib qwen_vl_utils einops seaborn
+
+# Check PyTorch installation
+python -c "import torch; print(torch.__version__)"
+```
+
+## 💡 Examples
+
+### Research Paper Analysis
+```bash
+# Index your research papers
+python -m apps.colqwen_rag build --pdfs ~/Papers/AI/ --index ai_papers
+
+# Ask research questions
+python -m apps.colqwen_rag search ai_papers "What are the limitations of transformer models?"
+python -m apps.colqwen_rag search ai_papers "How does BERT compare to GPT?"
+```
+
+### Document Q&A
+```bash
+# Index business documents
+python -m apps.colqwen_rag build --pdfs ~/Documents/Reports/ --index reports
+
+# Interactive analysis
+python -m apps.colqwen_rag ask reports --interactive
+```
+
+### Visual Analysis
+```bash
+# Generate similarity maps for specific queries
+cd apps/multimodal/vision-based-pdf-multi-vector/
+# Edit multi-vector-leann-similarity-map.py with your query
+python multi-vector-leann-similarity-map.py
+# Check ./figures/ for generated heatmaps
+```
+
+---
+
+**🎯 This integration makes ColQwen as easy to use as other LEANN features while maintaining the full power of multimodal document understanding!**