The invention discloses a bridge device. The bridge device comprises a machine base and a stone crushing machine arranged in the machine base; a fragmentation part is arranged in the stone crushing machine, a stone inlet is formed in the inner top wall of the right side of the fragmentation part, and a guide moving cavity is formed in the inner bottom wall of the left side of the fragmentation part; a lower discharge opening runs through the inner bottom wall of the fragmentation part on the right side of the guide moving cavity, and a conical groove is formed in the top of the lower dischargeopening; a lifting sliding block which extends upwards is connected with the interior of the guide moving cavity in a sliding and matched mode; the extension section of the top of the lifting slidingblock extends into the fragmentation part; the top, extending into the fragmentation part, of the lifting sliding block is provided with an arc-shaped surface extending to the right lower portion; afirst elastic element is arranged at the position, below the bottom of the lifting sliding block, in the guide moving cavity; a transmission groove is formed in the inner wall of the left side of thefragmentation part, a square groove is communicated with the interior of the inner top wall of the left side of the transmission groove, and a first guide moving groove extending up and down runs through the right side of the transmission groove. The bridge device is simple in structure and convenient to operate, improves the crushing effect of hardened fertilizer, reduces the manual workload, andimproves the stone crushing uniformity.