Surgical instrument and assembling method therefor

A surgical instrument, comprising a power source assembly, a power source assembly base for accommodating the power source assembly, and a power source discharging mechanism, wherein the power source discharging mechanism is mounted on the power source assembly;

• the power source discharging mechanism comprises:
• a circuit board, which comprises a discharging circuit, a conductive sheet, and a conductive contact surface that are integrated onto the circuit board, wherein the conductive sheet comprises a fixed terminal and an extension section;
• the fixed terminal of the conductive sheet is electrically connected to a first terminal of the discharging circuit;
• the extension section of the conductive sheet and the conductive contact surface switch between contact conduction and disconnection;
• the conductive contact surface is electrically connected to a second terminal of the discharging circuit;
• and
• a sliding member, which is able to slide between a first position and a second position, wherein when the sliding member is at the first position of the sliding member, the extension section of the conductive sheet is disconnected from the conductive contact surface, and the discharging circuit is in a turned-off state;
• and when the sliding member is at the second position of the sliding member, the extension section of the conductive sheet is in contact conduction with the conductive contact surface, and the discharging circuit is in a turned-on state.