The invention relates to a steel rail corrugation laser measuring device. The steel rail corrugation laser measuring device has a structure that: both ends of the device are provided with a bracket which can be arranged on a steel rail respectively; both sides of the top of each bracket are fixedly provided with guide rails; a sliding block is sleeved on the guide rails; the laser head of a laser displacement sensor is fixed to the sliding block; the serial port and the universal serial bus (USB) interface of the laser displacement sensor are connected with the serial port and the USB interface of a computer respectively; the bracket on one end is fixedly provided with a motor; the shaft of the motor is connected with a fixed pulley 1; the bracket on the other end is provided with a fixed pulley 2; one end of a steel wire is connected with the sliding block, and the other end of the steel wire rounds the fixed pulley 1 and the fixed pulley 2 and then is connected with the sliding block; the shaft end of the motor is connected with an incremental photoelectric encoder; and the signal output end of the incremental photoelectric encoder is connected with the control signal input end of the laser displacement sensor. The measuring device can conveniently measure the condition of corrugation on the surface of the steel rail in the site and has the advantages of high automation degree, convenience for operation, high measurement accuracy and high reproducibility of test data.