The utility model discloses an accessible main running gear who crosses track breach, including walking motor, walking main shaft, shaft joint and main dynamic wheel group spare, main dynamic wheel group spare symmetry sets up the both sides of the motor of being expert at, through the output shaft of walking main shaft and shaft joint and walking motor, main dynamic wheel group spare includes a polyurethane idler wheel, the 2nd polyurethane idler wheel, axle no. 1, axle no. 2, axle no. 3, first gear, second gear, axle no. 2 sets up in axle no. 1 with spool between three, a polyurethane idlerwheel with the 2nd polyurethane idler wheel set up respectively the axle draw axle on two, an axle draw the axle all be provided with first gear on two, the axle sets up the second gear on two, a gearengagement of second gear and both sides. The utility model discloses a walking motor passes through gear drive, forms the double drive wheel mode, just can cross the track breach accessiblely, simple structure, and cost economy has very strong market competition.