The device for raising electromagnetic compatibility of E1 unequilibrated interface includes sending module and receiving module. The sending module includes first external interface, first protection circuit, and first filtering circuit connected in series. The receiving module includes second external interface, second protection circuit, and second filtering circuit connected in series as wellas third filtering circuit connected between second external interface and second protection circuit. The external interface can bear +-1kV surge of lightning stroke between line-line and line-ground. Filtering circuit attenuates common mode signal 500KHz-800KHz more than 33dB, and attenuates common mode signal about 3MHz, 5MHz, and 7MHz more than 20dB so as to increase electromagnetic compatibility of E1 interface of existing equipment. Features are: passive element utilized and easy of implementation.