The present disclosure discloses a control circuitry of a smart wall switch. The control circuitry includes a primary step-down sub-circuitry, a secondary step-down sub-circuitry, an output control sub-circuitry, a microcontroller, an OTA (Over-the-Air) sub-circuitry, a three-way switch, a three-way switch conversion sub-circuitry, and a wireless communication sub-circuitry. An input terminal of the primary step-down sub-circuitry is connected to a power supply, an output terminal of the primary step-down sub-circuitry is connected to an input terminal of the secondary step-down sub-circuitry, and an output terminal of the secondary step-down sub-circuitry is connected to the microcontroller, an input terminal of the output control sub-circuitry is connected to the microcontroller, a first output terminal of the output control sub-circuitry is connected between the power supply and the primary step-down sub-circuitry, and a second output terminal of the output control sub-circuitry is connected to a load.