Downhole electric pulse technology is one of the new ways to achieve unblocked oil and gas wells to increase production, and the discharge switch is the basis to support its generation of shock pressure waves. A new type of oil and gas well production enhancement experimental device using thyristor series to constitute a discharge switch was designed for the disadvantage of uncontrollable discharge voltage of oil and gas well production enhancement device based on self-triggered gas switch. To ensure that the experimental device is safely used in high-power and high-voltage applications, static and dynamic voltage equalization circuits were designed to avoid overvoltage breakdown of the thyristor when the device is in operation. Using a field programmable gate array (FPGA) as the main control chip, the thyristor was controlled to conduct and discharge, achieving controllable adjustment of discharge voltage. The high-voltage energy extraction circuit was also designed to provide independent power supply for each thyristor drive circuit. The experimental results show that this device has good voltage clamp capability, precise discharge voltage control and obvious unblocking effect, which lays the foundation for the downhole operation of the new oil and gas well production enhancement device.