LED lamp emergency system based on constant current source

The invention discloses an LED lamp emergency system based on a constant current source. The system mainly includes a voltage-changing rectifying circuit, a filtering circuit connected with the voltage-changing rectifying circuit, a constant-current control circuit connected with the filtering circuit and an emergency illuminating circuit connected with the constant-current control circuit. In the constant-current control circuit, a constant-current control chip K is used. The LED lamp emergency system is capable of providing a constant current source for an LED lamp emergency system and preventing that current changes so that the illuminating effect of an LED lamp is affected.