Trash cleaning in modern buildings mainly relies on manual labor, which suffers from high intensity and low efficiency. Meanwhile, general mobile robots face issues such as poor path smoothness and low computational efficiency in complex environments like narrow corridors. To address these issues, a building trash bin handling robot was designed. First, the mechanical structure of the robot was designed, consisting of a two-wheel differential drive chassis module, a lifting module, and a servo-driven clamping module to ensure the stable grasping of trash bins. Then, a hierarchical control system was built based on ROS and μC/OS. Furthermore, an improved A^* algorithm was proposed, which adopted a hierarchical directional neighborhood search strategy to optimize search efficiency, introduced an adaptive dual-weight heuristic function to avoid local optimal solutions, and utilized a key node extraction strategy to remove redundant nodes, thereby achieving path optimization. Simulation results showed that search time was reduced by up to 44%, and the number of search nodes was reduced by 50%- 80%. The designed robot successfully completed autonomous navigation, inspection, and trash bin handling tasks in prototype testing, verifying its feasibility and effectiveness in building environments.