Lunar vehicle type stair climbing wheelchair

A lunar vehicle type stair climbing wheelchair comprises a chair body, a rack, front wheels and rear wheels, the front wheels are two sets of single steering wheels, and the rear wheels are two sets of driving wheels formed by connecting two wheels together. The front wheel comprises a wheel body, a left wheel cover, a right wheel cover, a transmission shaft, a worm gear reduction gearbox, a direct-current driving motor, a duplex shifting fork, a reversing motor, an internal spline three-position clutch, a bidirectional clutch mandrel, a first ratchet connecting rod disc, an arc-shaped connecting rod, a ratchet, a ratchet connecting rod disc clutch and a ratchet connecting rod disc clutch shifting fork. The rear wheels comprise the first rear wheel and the second rear wheel, the first rear wheel and the front wheel are the same in structure, and a transmission shaft of the first rear wheel is further sleeved with a synchronous gear. The second rear wheel and the front wheel are the same in structure, but the