The invention discloses a method for realizing automatic adjustment of LED (light-emitting diode) lamps. The method comprises the following steps of: sensing the peripheral light intensity information based on a light sensitive resistor; and adjusting the current passing through the LED lamps by modulating the duty ratio of PWM (pulse width modulation) by an adjustment potentiometer according to the light intensity information. The embodiment of the invention also discloses a device for realizing automatic adjustment of LED lamps. The device comprises a sensing module and a control module, wherein the sensing module is used for sensing the peripheral light intensity information based on the light sensitive resistor; and the control module is used for adjusting the current passing through the LED lamps by modulating the duty ratio of PWM by the adjustment potentiometer according to the light intensity information. The method and the device have the following advantages: the electric energy can be effectively saved by automatically dimming light according to the conditions of the surroundings, thus avoiding that desk lamps still emit light according to the same power under the condition that the light ray is brighter, ensuring fewer LEDs to emit heat and prolonging the service lives of the LEDs.