The present invention provides a medium material high-temperature complex permittivity measurement method based on terminal short circuit and pertains to technology of microwave and millimeter wave dielectric material complex permittivity measurement. When the present invention adopts the terminal short circuit for measurement of high-temperature medium material complex permittivity, a heat dissipation wave guide, a heat insulation waveguide, a high-temperature waveguide with a certain length, and a coupling device, a short circuit board are together constitute a reactive type resonator, and dimensions and microwave loss of the resonator under different temperature can be obtained by measurement of resonance frequency and quality factor of the resonator, and the complex permittivity of the medium material under the temperature can be further measured. The present invention is suitable for the measurement of the medium material high-temperature complex permittivity of various frequency band based on the terminal short circuit, and meanwhile the present invention can measure the dimension and the microwave loss of the waveguide resonator under different temperature. As the present invention considers the changing of the dimension and the microwave loss of the waveguide resonator caused by the influence of the temperature, the present invention has higher measurement accuracy and smaller error.