Electric device and switch device thereof

The invention discloses an electric device and a switch device thereof which are used for switching on and switching off a large current. The electric device comprises a thermal expansion chamber, anda moving main contact and a moving arc contact which asynchronously move in the same direction, and further comprise a first air compression chamber and a second air compression chamber. The first air compression chamber is communicated with the thermal expansion chamber, and a first air compression piston in the first air compression chamber is connected with the moving main contact; the secondair compression chamber is communicated with the thermal expansion chamber, and a second air compression piston in the second air compression chamber is connected with the moving arc contact; and theoperation directions of the compressed air of the first air compression piston and the second air compression piston are the same as the opening movement direction of the moving main contact. By adding the second air compression chamber, the second air compression chamber is connected with the moving arc contact, and the compressed air generated in the moving process of the moving arc contact is input into the thermal expansion chamber. Under the condition that the gas in the first gas compression chamber is little or hardly enters the thermal expansion chamber, the clean low-temperature gas in the second gas compression chamber can still be input into the thermal expansion chamber along with the movement of the second gas compression piston, and the arc extinguishing effect of the switchdevice is effectively improved.