The invention provides an adaptive leg stretching device which includes a base, wherein a slide way is arranged on the base, a left pedal and a right pedal are arranged on the slide way, a left positioning block is arranged on the left side of the left pedal, a right positioning block is arranged on the right side of the right pedal, a front baffle is arranged at the front end of the left pedal and the right pedal, a left baffle is arranged at the left end of the left pedal, a right baffle is arranged at the right end of the right pedal, both the left pedal and the right pedal include movableand fixed module, the fixed module is connected with the slide way, the movable module is connected with the fixed module through a compression spring, a switch is arranged on the base, the switch controls the closing of the movable module and the fixed module, the base is also provided with an upright post, and a object table is arranged on the upright post, the invention can effectively stretchthe leg muscles and improve the flexibility of the leg joints.