A two-level LED security light includes a power supply unit, a motion sensor unit, a time setting unit, a loading and power control unit, an external control unit, and a lighting-emitting unit. The LED security light is turned on at dusk for generating a first level illumination and turned off at dawn. When the motion sensor detects any intrusion, the LED security light is switched from the first level illumination to a second level illumination for a short duration time to scare away the intruder. After the short duration time, the LED security light returns to the first level illumination for saving energy. The light emitting unit includes one or a plurality of LEDs. The time setting unit is for managing illumination timing. The external control unit is for setting illumination characteristics of the first level illumination or the second level illumination of the light emitting unit.
