The invention discloses a pipe machining lathe with an automatic feeding function, and belongs to the field of pipe machining. According to the technical scheme, the pipe machining lathe with the automatic feeding function comprises a base, a clamping and cutting device and a feeding device, wherein the clamping and cutting device is arranged on the top of the base; the feeding device is positioned above the clamping and cutting device and comprises a support, a feeding mechanism and a conveying mechanism; the support is fixedly arranged on the upper surface of the base; the feeding mechanismis arranged on the support; the conveying mechanism is connected to one side of the feeding mechanism; the feeding mechanism comprises a feeding groove, a feeding cylinder and a separating cylinder; the feeding groove is obliquely formed in the top surface of the support; the feeding cylinder is detachably and fixedly connected to the side, which is close to the support, of the feeding groove; a groove is formed in the side, which is close to the support, of the feeding groove; and a first pushing cylinder is arranged on one side of the groove. The problem of manual feeding is solved, the effect of improving efficiency is achieved, and the pipe machining lathe with the automatic feeding function is mainly used for pipe machining equipment.