The present invention relates to a multi-wavelength and wide temperature Terahertz laser power meter calibration device and method. The method is based on the device and comprises: (1) testing the linear relation between the input power and the indicating value voltage of a Terahertz laser power meter; (2) setting operating wavelength of a set of Terahertz source according to the linear relation between the input power and the indicating value voltage in the step (1), and testing correction factors of the Terahertz laser power meter at different wavelengths; (3) setting a set of environment temperature according to the linear relation between the input power and the indicating value voltage in the step (1), testing correction factors of the Terahertz laser power meter at different temperatures, and calculating and obtaining the linear relation of a temperature correction factor [Beta] and the environment temperature T; and (4) correcting the test power of the Terahertz laser power meter when the wavelength and the environment temperature are tested. The multi-wavelength and wide temperature Terahertz laser power meter calibration device and method can improve the test accuracy of the Terahertz laser power meter at different environment temperatures so as to reduce the wavelength correction errors of the Terahertz laser power meter and improve the correction efficiency.