A relay protection device definite value region remote switching method comprises the steps that firstly, independent definite value region group numbers are formed; secondly, a current definite value region group makes a remote call; thirdly, a protection device definite value region group is set remotely; fourthly, a definite value is called; fifthly, the definite value is verified; lastly, a result is processed correspondingly according to the definite value. By the adoption of a flexible and efficient mode, a dispatcher can complete definite value calling and checking work including definite value region switching in an untended substation and verification of the definite value after switching in a dispatch room, and the purpose of dual confirmation after field definite value region switching is achieved by verifying the switched definite value region number and definite value calling and checking; as a result, manpower and materials required by operators to conduct definite value region switching on site, switching operation time and power supply time are saved, and stable operation of an electric power system and power supply reliability and power supply safety in production and life of people are better guaranteed.