The invention discloses a vehicle-mounted road surface crack detection system detection device based on the variable-depth cracks and aims at solving the checking problem of measurement results of different depths of cracks detected by a vehicle-mounted road surface crack detection system. The vehicle-mounted road surface crack detection system detection device based on the variable-depth cracks is mainly composed of rubber connecting pieces (1), cross bars (2), rubber (3), supports (4), a base (5), short supports (6), fixing shafts (7) and connecting pieces (8). The vehicle-mounted road surface crack detection system detection device based on the variable-depth cracks is provided and is variable in crack depth, simple in device structure, reliable in performance, easy and convenient to operate and install and low in cost.