主泵屏蔽电机是化工厂以及核电站的重要组成部分，主要用来运送高温、高压、毒性、腐蚀性、放射性的液体，其安全稳定的运行对化工厂及核电站回路系统非常重要。针对主泵屏蔽电机内发热与冷却的复杂性以及工作在密封高温条件下的特点，以一台5000 kW主泵屏蔽电机为例，采用温度场基本理论，用有限体积法对其端部齿压板和锥形环的温升进行数值计算，找到了工厂实验过程中电机端部温升“,”The canned primary pump motor which is mainly used to carry the fluid of high temperature, high pressure, radioactive, toxicity and causticity, it plays an important part in chemical plants and nuclear power stations. Therefore its safe and steady operation is very important to the loop system. Basing the complex of heating and cooling and the specialty of high temperature and air proof conditions, a physical model of three dimensional temperature coupled field for a 5000kW large canned motor of the primary pump was established in this paper. During the delivery test, abnormal temperature occurred in the finger plate. The temperature of the finger plate and the cone ring was calculated using the finite volume method. Calculation results revealed the cause. Thus the configuration was modified. A new connecting scheme of finger plates with insulation and the cone ring was provided. The overheat problem at the motor’s end was resolved. Furthermore, the theory and practice basis will be provided for cooling structure design and temperature calculation accurately of canned primary pump motors of larger capacity.