Protection circuit, battery management system and electric device

The utility model discloses a protection circuit, a battery management system and an electric device. The protection circuit is used for protecting the controller, the controller is powered by the first power supply module, and the protection circuit comprises a control module and a pull-down module; the control module is connected with the pull-down module, and the pull-down module is connected with the signal input end of the controller; and the control module is used for controlling the pull-down module to pull down the voltage accessed to the signal input end of the controller under the condition that the first power supply module stops supplying power to the controller. According to the embodiment of the invention, when the controller is in the power-off state, the voltage received by the controller can be lowered, so that the controller is protected from being damaged due to overvoltage.