The invention relates to a rebar mechanical connection torque automatic detection tool. The automatic detection tool is characterized in that the automatic detection tool comprises a test head and a host computer; the test head is connected with the host computer through a data line; the test head comprises a sleeve fixing ring, a rebar fixing ring and a connection rod; the sleeve fixing ring is fixed on a sleeve; the rebar fixing ring is fixed on a rebar; the sleeve fixing ring and the rebar fixing ring are connected through the connection rod; a torque rod is arranged on the connection rod;and a dynamic torque sensor is arranged between the rebar fixing ring and the connection rod. According to the invention, the rebar mechanical connection torque automatic detection tool has the advantages of reasonable structure and convenient use; the operation difficulty and complexity are reduced; a detection result is directly displayed; and personal injury caused by a wrench during manual operation is avoided.