The invention discloses a buckle device with a safety belt multi-gear height adjusting function. The buckle device comprises a plate body, chutes, lock catches and a lock pin. Side protecting plates are arranged on the two sides of the plate body, and the adjusting lock catches are arranged in the middles of the side protecting plates at intervals. Triangular grooves are formed in the edges of thelock catches, and the tensile strength of the lock catches is improved. The chutes are formed in the inner sides of the side protecting plates, and sliding blocks are provided with the round-head long lock pins capable of automatically stretching out and drawing back through control by springs. The sliding blocks slide in the chutes, when the lock pins slide to the lock catches, the lock pins automatically drop into the lock catches, clamping is achieved, and certain height adjusting is completed. According to the buckle device, through multiple improved design of plates, the sliding blocks and the chutes, the body weight is greatly reduced, and the lightweight requirement is met; through the structure of the double-row lock catches, clamping is stable and firm, and positioning clamping pieces at the two ends are prevented from slipping out; the potential safety hazard is eliminated, the extreme value reaches, the problem that the structure of an existing height-adjusting device is complex is solved, and the high performance is achieved; and mounting and fixing are conducted through wing clamps, the universality is high, and a novel height-adjusting device is suitable for variousvehicle types.