The invention relates to the technical field of electric wire machining, and discloses a cutting device for electric wire machining. The cutting device comprises a rack. A conveying mechanism is arranged on the rack and comprises a driving wheel. A workbench, a limiting plate and a cutting mechanism are in sliding connection to the rack. Multiple limiting grooves used for containing electric wiresare formed in the workbench. A first drive mechanism used for driving the limiting plate to slide is arranged on the rack. An air supply box, an air guide box and a cylinder body are fixedly connected to the rack. A first guide pipe communicates between the air supply box and the air guide box, and a three-way valve is arranged on the guide pipe. A second guide pipe is connected between the cylinder body and the three-way valve. A turbine coaxially connected with the driving wheel is rotationally connected in the air guide box. A piston is in sliding connection in the cylinder body. A first spring is connected between the piston and the cylinder body. A piston rod fixedly connected with the workbench is fixedly connected to the piston. An air outlet hole is formed in the cylinder body. The cutting device solves the problem that in the prior art, due to improper cutting, the percent of pass of finished products of an electric wire cutting device after machining is low.