The invention relates to a crushing device, namely a roller type crusher for producing a compound fertilizer. The roller type crusher comprises a frame, a fixed roller and a flexible roller, wherein the fixed roller is connected with the frame, a flexible seat is arranged on the frame, the flexible roller is arranged on the flexible seat, a spring is arranged between the flexible seat and the frame, a position limiting rack is connected with one side of the flexible seat far away from the spring, a push rod is rotatably connected with one side of the position limiting rack far away from the flexible seat, an optical rod part is arranged on one side of the push rod near the position limiting rack, a screw part is arranged on one side of the push rod far away from the position limiting rack, a screw hole cooperated with the push rod is formed on the frame, the screw part of the push rod passes through the screw hole, a cylinder is arranged above the frame, a clamping block is arranged on the output end of the cylinder, and a clamping groove of the clamping block is arranged on the flexible seat. The problem of the prior art that the separation size of the existing roller type crusher cannot be adjusted is solved, and the roller type crusher can crush raw materials into different sizes.