The invention discloses a super-capacitor stand-by power source circuit for a gate and aims to solve the problem of failure to realize automatic charging according to the voltage of a stand-by power source and to realize automatic switching off under an insufficient voltage condition in the prior art. The super-capacitor stand-by power source circuit for the gate comprises an input port, an outputport, a standby power source, an input control module, an output control module, a voltage division module connected with the standby power source, and a current limiting module which is connected with the input control module in parallel; the input port is connected with the input end of the input control module; the output end of the input control module is connected with the positive end of asuper capacitor; the positive end of the super capacitor is connected with the input end of the output control module; the output end of the output control module is connected with the output port; and the output end of the voltage division module is connected with the control ends of the input control module and the output control module. According to the super-capacitor stand-by power source circuit for the gate of the invention, the charging process and power supply disconnection of the standby power source are automatically controlled according to the magnitude of voltage, and therefore, external equipment is not influenced by low voltage, the reliability and practicability of the circuit are ensured; and the circuit is environment-friendly and has a long service life.