The embodiment of the invention discloses a mechanical test device which comprises a test device body, a test hole connection line, a plurality of circuits, a knob, a drive plate, a connection rod and a change-over switch, wherein the test hole connection line is arranged on the test device body, and the circuits are arranged in the test device body; one end of the knob is arranged in a shell body of the test device body while the other end of the knob is exposed out from the shell body; the drive plate is sheathed on a part of the knob arranged in the shell body and can synchronously rotate along with the knob and a track formed by a plurality of arc segments with different radii is arranged on the surface of one side of the drive plate; and one end of the connection rod is connected andmatched with the track while the other end of the connection rod is in contact with the change-over switch so as to drive the change-over switch when the connection rod moves up and down and change the connection between the test hole connection line and the circuits. By utilizing the device, an operator can realize the test of a plurality of test gears by inserting a probe in the test hole and screwing the knob without repeatedly inserting and pulling out the probe, so that the work efficiency is improved and the error probability is reduced.