The induction motor with heavy rotary inertia load is a specialized motor which drives the coal mill in the power station. Due to the heavy rotary inertia, the large starting current and long starting time resulting from the coal mill with heavy rotary inertia load, the loss and heat problems of the motor rotor in the starting process are more serious. To improve the starting reliability of the motor, an induction motor which is the largest capacity with heavy rotary inertia load in China is chosen as the research object. By the methods of discrete point calculation and curve fitting, the models of rotor core loss, rotor copper loss and rotor surface heat transfer coefficients with the change of rotor speed are established respectively at the starting process. And then, the rotor loss and the temperature rise at the starting process are calculated and analysed by the finite element method. The results show that the starting time of the motor is as long as 48 s. The rotor core loss, rotor copper loss and rotor surface heat transfer coefficients change with the rotor speed at the starting process. When the starting is completed, the highest rotor temperature rise is 141.1 K.