Focused on the issue that the sorting operation mechanical arm which used Case-Based Reasoning (CBR) mechanism could not be used for the complex scenario with a lot of object information, an improved Case-Based Reasoning-Belief, Desire, Intention (CBR-BDI) reasoning mechanism was proposed. Firstly, the input information was regarded as belief, and the case properties obtained through sentence segmentation and retrieval was regarded as desire. Secondly, map matching, desire analysis and guidance were added to perfect desire. Finally, complete desire generated solution which was regarded as intention. In the scenario of multiple object and information, users could command system for sorting operation through dialogue. The experimental results show that compared with the traditional CBR mechanism, the improved CBR-BDI reasoning mechanism possess the ability of analysis and guide, and can be used for the scenario of multiple object and information.