The canned motor for chemical pump is the main power source of chemical pump. It has the advantages of reliable operation and no medium leakage. It is very important to analyze its operating performance and multiphysics distribution. A new composite squirrel cage structure is designed for the canned motor for chemical pump. The size is determined by the commercial field-circuit coupling time-step finite element software, and its driving performance is analyzed. Based on the idea of fluid-solid coupling, the three-dimensional temperature field and stress field distribution of the new composite squirrel cage structure and the conventional pure copper squirrel cage motor are compared and analyzed. Through experiments and analytical calculations, the new canned motor for chemical pump designed is verified. The composite squirrel cage structure and the motor scheme are reasonable and feasible. On the premise of ensuring the energy index, the starting torque multiple is increased by 2.1%, the starting current multiple is reduced by 2.6%, and the winding end temperature is reduced by 3.18 ℃. In addition, the weight and cost of the motor are reduced.