Adjustable discharging gap experimenting device in closed space

The invention relates to an experimenting device, in particular to an adjustable discharging gap experimenting device in a closed space, and aims to solve the problem that a discharging gap experimenting device tank is poor in sealability. The adjustable discharging gap experimenting device comprises a glass steel tank, a discharging electrode, a grounding electrode, a high-voltage lead lead-in end cap, a linear motor, a displacement sensor, an optical fiber and an optical fiber lead-in end cap, the discharging electrode, the displacement sensor, the grounding electrode and the linear motor are all arranged in the glass steel tank, a first port is arranged at the top end of the glass steel tank, the high-voltage lead lead-in end cap is arranged at the first port, a high-voltage lead is led in through the first port to provide voltage to the discharging electrode, the discharging electrode is connected with a secondary stage of the linear motor, a primary stage of the linear motor is fixed while the second stage of the same is movable, the discharging electrode is positioned above the grounding electrode, and the displacement sensor is connected with the secondary stage; the glass steel tank is provided with a second port, the optical fiber lead-in end cap is arranged at the second port, the optical fiber is led in through the second port, and a light sensing end of the optical fiber is positioned at a discharging gap between the discharging electrode and the grounding electrode. The adjustable discharging gap experimenting device is used for discharging gap studying.