The invention discloses a chamfer tool special for a lathe. The chamfer tool special for the lathe comprises a tool handle and a tool bit arranged at the front end of the tool handle, the tool bit is provided with a blade mounting step, a blade of a plate-type structure is provided with a blade mounting hole, the blade is arranged on the blade mounting step in a left-right movement mode through a blade screw inside the blade mounting hole, the left side and the right side of the front end portion of the blade are provided with a left cutting edge and a right cutting edge, and the included angle between cutting edge line of the left cutting edge and the cutting edge line of the right cutting edge is the angle of tool nose. The chamfer tool special for the lathe effectively solves the problems of low processing efficiency and high production costs when a turning tool in the prior art is used for chamfering a groove of a cylindrical surface, also solves the problem of long processing time due to the fact that polishing or deburring needs to be performed independently in the lathe processing in the prior art, can greatly shorten the processing time, improve product quality and reduce production costs and has very high practical values.