The utility model discloses a rear cover installing structure for band-type brakes of crane motors, which comprises a cover body and a motor spindle, wherein the a part, extending out of the outer side of the cover body, of the motor spindle is sequentially sleeved with a casing pipe, a baffle and an elastic washer from inside to outside, and the outer side of the elastic washer is provided with two fastening nuts which are in threaded connection with the motor spindle. By adopting the technical scheme, through lengthening the motor spindle, additionally providing the casing pipe, the baffle and the elastic washer, and fixing the cover body by using two fastening nuts, a band-type brake is easier to adjust and firmer, and in the process of frequently starting and stopping a motor, a phenomenon of unscrewing the fastening nuts is eliminated, thereby fully improving the safety of the lifting operation of a crane.