A single-crankshaft fender trim plate slope type snowboarding trainer consists of a front arc-shaped base frame, a rear arc-shaped base frame, a middle slope support, a side slope support, a closed arc gradient plastic plate, a single-crankshaft fixed treading slide plate with pulleys, a rebounding rubber belt, a guiding horn base, an arc-shaped plate slope type slide way, a gantry hanger frame, a sliding suspender belt ring, an elastic safety belt and the like. When a sporter performs training, double feet are locked on a foot shoe taking-off device treading slide plate with a single crankshaft wheel, the sporter performs pedaling with strength to enable the pulleys to incline towards one side and enable rolling wheels at the shaft end to roll towards a side slope, and the belt moves and pulls the rebounding rubber belt. When the body performs lateral movement and falls at a certain angle, the slide plate is controlled with double legs and is gradually turned inward to simulate the rotation radian, then the sporter repeats the actions again in the reverse direction and circularly acts in the horizontal direction to simulate various rotary snowboarding actions on snow and improve the specialized strength capacity.