Aiming to simultaneously detect mechanical and insulation defects in gas insulated switchgear (GIS), this paper proposes a low-power smart wireless vibration acceleration-acoustic emission combined sensor. The design and simulation verification of the sensor fusion structure are conducted, utilizing bluetooth low energy (BLE) to establish communication between the sensor and the client. For the first time, pseudo-random M-sequences are applied to the impedance response self-calibration of a piezoelectric sensor, requiring only milliseconds and milliwatts for a single calibration. The test results show that the average vibration sensitivity of the sensor is 511 mV/ g within the frequency range of 100 Hz to 2 kHz, and the ultrasonic sensitivity is stabilized between 70 to 90 dB within the frequency range of 20 to 100 kHz, with a relative uncertainty of less than 2% . The data transmission rate exceeds 1 Mbps when the working distance is less than 8 m. A combined mechanical vibration-partial discharge test is conducted on the actual GIS equipment installed with metal particle defects. The results demonstrate that the sensor can achieve simultaneous and co-located measurement of mechanical vibration and ultrasonic signals from the equipment. This offers a novel and efficient approach for distributed detection of the operational status of power equipment.