1. A millimeter-wave inspection apparatus, wherein the millimeter-wave inspection apparatus comprises: optics devices, configured to receive millimeter-wave energy radiated from an object to be inspected and focus the received millimeter-wave energy; a radiometer receiving device configured to receive the focused millimeter-wave energy and transform the millimeter-wave energy into electrical signal; an imaging device configured to generate a temperature image of the object to be inspected in accordance with the electrical signal; and a radiometer temperature calibration device, which comprises: a normal temperature calibration mechanism, having a calibration temperature equal to the current environment temperature, to calibrate the initial value of the radiometer; and a high temperature calibration mechanism, having a calibration temperature higher than the current environment temperature, to cooperate with the normal temperature calibration mechanism for calibrating the gain of the radiometer, wherein the normal temperature calibration mechanism comprises a rotatable normal temperature calibration hollow cylinder assembly and a second driving motor to drive the normal temperature calibration hollow cylinder assembly to continually rotate around the radiometer.