The invention provides a method and device for all-directional induction stepless dimming of an LED lamp. The device comprises an LED lamp power supply main circuit internally provided with a dimming control unit and a primary side main control unit and a human body induction unit used to introduce human body induction signals into a control chip. A PWM duty cycle signal is output by the control chip and is finally transmitted to a source of a field effect transistor Q6 to drive an oscillation transformer T1 to generate an alternating voltage, and a driving voltage is output to an LED lamp after rectification filter. Compared with the prior art, people approaching in two very opposite directions can be monitored at the same time, the brightness of the lamp is adjusted by adjusting the PWM duty cycle on the primary side of a power supply.