The invention discloses an evaluation device for environmental electromagnetic compatibility of a power transmission and transformation primary equipment testing device. The evaluation device is characterized by comprising a power supply module, a serial port communication module, an AC parameter high-speed sampling module, a harmonic signal output module, a man-machine interface module and a main system module, wherein a power supply output end of the power supply module is connected with a power supply input end of the main system module, a man-machine interface control signal line of the main system module is connected with a signal interface of the man-machine interface module, a communication line of the main system module is connected with a communication interface of the serial port communication module, AC voltage and AC current simulation signal input ends of the main system module are connected with an AC parameter simulation signal output end of the AC parameter high-speed sampling module, a signal line of the main system module is connected with a signal interface of the harmonic signal output module, and the serial port communication module is connected with a computer platform externally for transmitting data to the computer platform for analysis.