Abstract: Aiming at the existing status of energy waste caused by rotor series resistance speed-regulation of electrical control system of mine hoist with medium and small power,the paper proposed a design scheme of new type of dual-PWM frequency-conversion speed-regulation system.The mathematical models of three-phase voltage-source type PWM rectifier were established in three-phase static coordinate system and two-phase rotating d-q coordinate system separately.Its feedforward decoupling control strategy and realization of DSP were researched.Position and operation time of voltage space vectors of converter were calculated directly according to reference voltage space vectors output by current regulator and realization method of DSP was given.The simulation result verified the validity of the scheme.