The invention discloses an electromagnetism separating-closing-type repeating folding and unfolding unlocking wheel mechanism. Folding and unfolding motion of a wheel is achieved through closing and separating of an electromagnetic clutch, namely, when the clutch is closed, an inner transmission shaft and an outer thread shaft synchronously rotate, a composite-motion-type push seat hinged on a sliding nut conducts composite motion along the axial direction and the circumferential direction, a spoke pull rod hinged with the composite-motion-type push seat conducts plane composite motion in a rotation plane to further drive a sliding spoke fixedly connected on a wheel rim inclined block to move along the radial direction to achieve adjustment of radial sizes of the wheel; and when the clutch is separated, a wheel hub, a wheel shaft, a spoke and a wheel rim of the electromagnetism separating-closing-type repeating folding and unfolding unlocking wheel mechanism form an integral wheel, the wheel is in a locking state, and the driving function of the wheel can be achieved by driving the wheel to rotate. The electromagnetism separating-closing-type repeating folding and unfolding unlocking wheel mechanism can achieve effective adjustment of the radial sizes of the wheel according to different terrain conditions, overcome the defects that the prior motion obstacle crossing robot car is bad in adaptive capacity of unstructured and complex terrain, and effectively improve terrain adaptability of the wheel.