This paper studies a soft starter of six-phase BLDC motor, presents a soft start method based on complex programmable logic device (CPLD), analyzes the soft starting process of six-phase BLDC motor and the influence of PWM carrier frequency and duty on starting process, employs back EMF zero crossing detection circuit to detect the rotor position, designs the hardware circuit and program of the soft starter, and finally verifies the validity of the proposed method by the experiment. The experimental results show that the soft starter based on CPLD is simple, reliable and practical.