The invention relates to a lift, in particular to a positioning device of the lift, and belongs to the technical field of lifts. The positioning device for the lift comprises a positioning air cylinder, a positioning rod seat plate and a positioning plate, the positioning plate is provided with a positioning gap, and a positioning rod is fixed on the positioning rod seat plate. The upper end of the positioning rod seat plate is hinged to a lug plate through a pin shaft, the lower end of the positioning rod seat plate is hinged to a piston rod connector through a pin shaft, the piston rod connector is connected with a piston rod of the positioning air cylinder, the tail end of the positioning air cylinder is provided with a positioning air cylinder connector, the positioning air cylinder connector is hinged to a positioning air cylinder seat through a pin shaft, and under pushing of the positioning air cylinder, the positioning rod on the positioning rod seat plate can enter the positioning gap of the positioning plate. According to the positioning device of the lift, a lifting cage can be kept stable in the process that cargoes enter and exit the lifting cage of the lift, the working efficiency of cargo carrying is improved, and the safety is improved; meanwhile, the lifting cage and a fixed vertical column can be accurately positioned, therefore, the height difference between the lifting cage and the entering and exiting ground can be avoided, and the cargoes can enter and exit the lifting cage conveniently and rapidly.