Abstract: In order to ensure the safe operation of the multi-ropes friction hoist, the diameter of the rope groove should be the same. A frictional lifter drum rope groove parameter detector based on laser ranging is proposed. Firstly, the measuring instrument measures the analog signal of the rope groove radius through the laser sensor. Then, the analog signal is converted into a digital signal that single chip microcomputer can process through A/D conversion. After data reading and processing, the measured results are displayed in real time by the DWIN LCD screen, and the radius changes of the rope grooves are graphically displayed. The drum rope groove parameter measuring instrument can accurately measure the radius of the rope groove and accurately display the measurement result, so that the operator can know the working condition of the drum in time and ensure the safety of transportation promotion.