The invention relates to a door lock mortising machine which comprises a transverse beam, a transverse guide rail, a chassis, a vertical guide rail, a fixed bracket, a motor, a rocker arm end support, a cavity, a lifting poker, a transmission shaft, a crank, a rocking bar, an oscillating arm, a rocker arm, a reducing sleeve, a tool bar, a tool bit, clamping boards, a bidirectional lead screw and a hand wheel. Compared with the prior art, the door lock mortising machine has the advantages that the door lock mortising machine can locate on a wood door accurately and move precisely, a side hole positioner is used for machining a lock hole of the wood door, the lock hole can be machined through one-step installation, positioning and puncturing instead of through a plurality steps and a plurality of machines, work efficiency is improved, the labor intensity of workers is reduced, and the door lock mortising machine is simple and convenient to use, accurate and fast in positioning, safe and reliable in operation, small in seize, convenient to carry and suitable for machining lock holes in various wood doors.