The invention discloses a magnetic field interference generating device for verification of an iron-core earth current tester. The device comprises a support; inductance coils are arranged at the two sides of the support; each inductance coil is connected with an output terminal of a voltage regulator; and the input terminal of the voltage regulator is connected with a power supply. A magnetic field interference region is formed between the two inductance coils; and a tested piece fixing tool is arranged in the magnetic field interference region. According to the invention, a stable magnetic field can be generated; the electrical safety performance is high; the structure is reasonable; and the verification work can be carried out successfully.