The invention relates to a thorough power off system after shutdown of a transformer, belonging to transformers in the power field. A power input end, a device power supply end, and a silicon controlled rectifier between the power input end and the device power supply end are included. The thorough power off system is also included. The thorough power off system comprises a casing, the casing is internally provided with a spring mechanism, the spring mechanism comprises a spring and a rotating shaft placed in the middle of the spring, and at least one end portion of the rotating shaft is provided with gear teeth at the outer side. The thorough power off system comprises a switch button, the switch button comprises a button and a connecting rod mechanism, one side of the connecting rod mechanism is provided with a tooth bar that matches the gear teeth, the top of the casing is provided with an opening, the button is placed in the opening, and the connecting rod mechanism extends into the casing. An induction coil is embedded into the sidewall of the casing, and connected with the signal input end, and a permanent magnet is fixed on the rotating shaft. When there is no current, the silicon controlled rectifier forbids pass of current, and energy waste is further avoided.