Abstract: Based on analysis of six-pulse-wave AC/AC frequency converter and according to principle of dual-slope voltage soft starting method, a frequency division starting method based on six-pulse-wave AC/AC frequency converter was put forward. When motor is starting, corresponding output voltage required the minimum torque value is exerted on stator side of motor directly and then the voltage is increased progressively to the final desired voltage based on the principle of AC/AC frequency converter and thyristor trigger rules. The simulation results show that the method can control stator current effectively and obtain good torque curve in frequency division starting process, improve starting performance of motor through selecting converter output voltage and adjusting running time of each level reasonably.