A portable medium loss angle standard checking device comprises a housing, terminals, a parallel circuit and a serial circuit. The upper part of the housing is provided with seven terminals which are used for connecting with a medium loss instrument. The housing is internally provided with the parallel circuit and the series circuit. The parallel circuit is a positive wiring measurement mode for checking the medium loss instrument, and the serial circuit is a negative wiring measurement mode for checking the medium loss instrument. The portable medium loss angle standard checking device has a beneficial effect of high environment adaptability. Because the totally shielded housing is utilized, the device can be used at any condition. High accuracy of a measured reference value is realized. Because a standard capacitor and a standard resistor are used as assembly, a reliable checking value is supplied. A flexible use method is realized. Because an adjustable design of an RC circuit which has a plurality of measurement reference amounts is adopted, comparing checking is realized. High insulation performance and long service life are realized. Because a pure magnetic miniature insulator is utilized as a leading-out terminal, high insulation reliability is realized and a risk of service life reduction by insulation cracking is reduced.