The invention provides a double-air-chamber high-voltage switch on-off performance simulating testing device which comprises a pressure container, a moving arc contact and a static arc contact. The static arc contact is transmissbly connected with an operation mechanism. The moving arc contact is mounted in the pressure container through a contact seat. The contact seat is provided with an expansion air chamber which comprises a nozzle and fixed volume. The contact seat is internally provided with a separator plate which is separately arranged with the expansion air chamber. The separator plate, the outer wall of the expansion air chamber, and the corresponding segment of the contact seat form an energy storage air chamber. The wall of the expansion air chamber is provided with communicating holes for communicating the expansion air chamber and the energy storage air chamber. The expansion air chamber is provided with a first sensor for detecting the air pressure in the expansion air chamber. The energy storage air chamber is provided with a second sensor for detecting the air pressure in the energy storage air chamber. The double-air-chamber high-voltage switch on-off performancesimulating testing device is advantageous in that instantaneous movement of a sensor is prevented; high reliability of a measurement result is ensured; the sensor records the air pressure changes of double air chambers; and the relation between the air pressure changes of the double air chambers and the on-off performance can be obtained through an arc quenching characteristic.