The invention provides a decelerating electronic safety clamp system of a high-speed elevator. The decelerating electronic safety clamp system is mounted on the vertical elevator and comprises a speedencoder, a position encoder, a main control system, a trigger circuit, a deceleration friction device and an electronic safety clamp. Through double-calibration redundancy design of the speed encoderand the position encoder and by utilizing a double position and speed recognition system of the speed encoder on a host and the absolute value position encoder in a hoistway, electronic safety clampmisoperation caused by single detection is avoided, inertial impact force generated by the speed is weakened, and the personal safety of an elevator taking person is protected; and meanwhile, a control method of the decelerating electronic safety clamp system is provided, and thus the decelerating electronic safety clamp system is safer and more reliable.