The invention discloses an auxiliary robot for tumor puncture of four degrees of freedom, and belongs to the technical field of surgical instruments. The robot comprises a needle inserting device, a first swing drive device, a second swing drive device, a first parallel moving drive device and a second parallel moving drive device. The needle inserting device is used for finishing puncture actions, the first swing drive device is used for driving the needle inserting device to swing around Y axis, the second swing drive device is used for driving the needle inserting device to swing around X axis, the first parallel moving drive device is used for driving the needle inserting device to move in parallel along the X axis, and the second parallel moving drive device is used for driving the needle inserting device to move in parallel along the Y axis. By utilizing the robot, the automation and intelligence of mechanical needle inserting can be achieved, the surgery process is standardized,the influence of human and experience factors is reduced, the working strength of physicians is reduced, the working efficiency of the physicians is improved, and the accuracy and success rate of thesurgeries are improved.