The invention provides an adjustable voltage-stabilizing automatic power-off relay which comprises a shell, a voltmeter, a power-on switch, a load device, a resistance regulator, a capacitor and a power-off switch, a power input part and a power output part are arranged on the shell, and the power-off switch is electrically connected with the power input part, one side of the power-on switch and the load device. The other side of the power-on switch is electrically connected with the load, the resistance regulator and the capacitor. The voltmeter is fixedly connected to one side of the shell, faces the outside and is connected with the power output part in parallel. According to the invention, the load device is adopted to consume an out-of-range input voltage, and meanwhile, the capacitor is used to carry out follow current on power utilization of an external electric appliance, so that continuous operation of the external electric appliance is guaranteed; and the resistance regulator is adopted to regulate the voltage output by the power supply output part so as to adapt to the requirements of various electric appliances, so that a user can have multiple purposes, and relay resources are saved.