Lower limb rehabilitation exercise device used on bed

The utility model relates to the technical field of lower limb rehabilitation exercise, and discloses a lower limb rehabilitation exercise device used on a bed, which comprises a bottom plate, a leg exercise mechanism is arranged on the bottom plate, the leg exercise mechanism comprises a first fixing plate, the first fixing plate is fixedly connected to the bottom plate, a first sliding groove is formed in the first fixing plate, and a second sliding groove is formed in the second fixing plate. A first sliding block is connected into the first sliding groove in a sliding mode, a pedal rod is rotatably connected to the first sliding block, a pedal plate is fixedly connected to the pedal rod, a bandage is arranged on the pedal plate, rotating blocks are rotatably connected to the two ends of the pedal rod, and a second fixing plate is fixedly connected to the first fixing plate. A first spring is fixedly connected between the rotating block and the second fixing plate. According to the leg rehabilitation train