The invention relates to a three-phase squirrel-cage asynchronous variable frequency motor for a crane; the motor comprises a housing, a central shaft, a rotor, a stator core, a normally closed electromagnetic brake and a cooling blower; the front end of the central shaft horizontally penetrates the housing and a penetrating end thereof is provided with an output connecting sleeve via a spline; the cooling blower employs a single axle-flow blower, and is mounted right behind the normally closed electromagnetic brake in the housing via a blower rack; the cooling blower employs independent powersupply, and blades of which are inclined and gradually distort along the radius direction. The three-phase squirrel-cage asynchronous variable frequency motor is simple and reasonable in structure design, can fully satisfy crane conditions and crane work mechanism features, can solve harmonic wave pulsation and noises caused by a general variable frequency motor, and can solve the problems that the general motor is large in size and high in energy consumption.