Induction motors in elevator equipment usually use a soft starter with three-phase six anti-parallel thyristors as the driving device to achieve soft start of the motor and to reduce energy consumption. Under the forced commutation of the thyristor, the stator voltage and current produce certain amounts of harmonics, which bring losses to the motor and even affect the operation of the elevator. Aiming at this problem, taking the thyristor-driven induction motor system as the research object, the circuit mathematical model of this object is established, the variable voltage constant frequency (VVCF) mode is adopted, the harmonic spectrum characteristics of each order are calculated, and a new compensation control law is designed. The calculation results and compensation results are verified by computer simulation, and the experiment proves that this method is effective.