Deep Search is a new search feature introduced by Microsoft Bing, which leverages generative AI models such as GPT-4 to expand and understand complex search queries, providing more relevant and comprehensive search results. This feature can delve deeply into the web to find information unattainable by general searches. Key features include: understanding search intent, extending search terms; deeply searching related pages; and sorting results by relevance. It is suitable for cases where general searches are insufficient and more comprehensive and accurate answers are needed. Empowered by AI, it significantly enhances the quality of Bing search.