The invention discloses a mine-hoist constant deceleration safety braking system and a braking method thereof, and relates to the technical field of mine-hoist safety braking control. The system comprises a disk brake, a hydraulic station, an electric control device and a detection feedback device which are arranged on a drum brake disk, wherein a speed sensor arranged on the drum acquires a hoist deceleration signal and inputs the hoist deceleration signal into the electric control device; the electric control device receives the signal and compares the signal with the given speed value to send out a control command; after the control command is processed into an electric signal and compared with an oil pressure signal which is fed back by a pressure sensor on the hydraulic pipeline arranged between the outlet end of an electrohydraulic proportion reversing valve and the disk brake cylinder, an electric signal control command is sent out; and the electrohydraulic proportion reversingvalve of the hydraulic station outputs a hydraulic pressure signal, which varies as the input control command varies, so as to control the motion state of the hoist by the disk brake, thereby realizing constant deceleration safety braking of the mine hoist.