The invention discloses a built-in photoelectric integrated sensor used for detecting insulation defects of gas-insulated switch equipment, which comprises a main cover plate, an ultrahigh-frequency sensor, a joint, an optical probe, and is characterized in that the main cover plate is provided with a first end face and a second end face in the axial direction; the ultrahigh-frequency sensor is arranged at the second end face; the joint is arranged at the first end face, and the ultrahigh-frequency sensor is connected with the joint; the optical probe is arranged on the main cover plate and comprises a connecting assembly and a columnar light guide bar, the connecting assembly is provided with a first end and a second end, the first end is connected with the first end face of the main cover plate, the second end of the connecting assembly is provided with an optical fiber interface used for being connected with an optical fiber, the light guide bar is provided with a near end and a far end, the near end of the light guide bar is arranged in the connecting assembly, and a light guide hole is reserved between the optical fiber interface and the near end of the light guide bar. The sensor disclosed by the invention is not suitable for performing detection on partial discharge according to an ultrahigh frequency method, but also can perform optical detection.