The invention discloses an equivalent device for millimeter wave radiometer test. The device comprises a microwave anechoic chamber, a millimeter wave radiometer detector, a dielectric attenuation module, a target jammer, a three-dimensional test platform, a detector output signal acquisition module, a chopper wheel, a chopper wheel control and rotation speed monitoring module and a test platform servo control module. The transmitting antenna of the target jammer, the chopper wheel, the dielectric attenuation module and the receiving antenna of the millimeter wave radiometer detector are on the same straight line. The target jammer is arranged on the three-dimensional test platform. The test platform servo control module is used for controlling the height, the pitch angle and the azimuth angle of the target jammer through the three-dimensional test platform. The chopper wheel control and rotation speed monitoring module is used for controlling the rotation speed of the chopper wheel. The detector output signal acquisition module is used for acquiring a millimeter wave signal detected by the detector. According to the invention, static and dynamic performances of a millimeter wave radiometer can be tested; the detection cost of a product is reduced; and the test efficiency is improved.