Interlocking device of main-auxiliary box structural gearbox assembly

The utility model belongs to categories of automobile gearboxes, and particularly relates to an interlocking device of a main-auxiliary box structural gearbox assembly. The interlocking device comprises a main box and an auxiliary box. The main box has multiple gear positions, and the auxiliary box has two gear positions. Through the linkage of the main box and the auxiliary box, main-auxiliary box multiple gear position equal ratio range speed ratio is achieved. The interlocking device is characterized in that the main box gear position switchover is manipulated in a mechanical method, the auxiliary box high-low gear switchover is manipulated to complete in a pneumatic method, an air hole is formed in the middle of an auxiliary box cylinder, a path of air source is led out for manipulating a locking mechanism of a main box control mechanism, the air source air path is closed before gear shifting of the auxiliary box cylinder is not finished, the main box control mechanism is locked, after gear position switc