Grain crushing machine for agriculture

The invention discloses a grain crushing machine for agriculture. The grain crushing machine for the agriculture includes a grain crushing machine body and a grain collecting box, the grain crushing machine body includes a feeding inlet in the top, a discharging outlet in the bottom, a crushing cavity located between the feeding inlet and the discharging outlet and a filtering mechanism located between the feeding inlet and the discharging outlet, a primary grinding mechanism and a secondary grinding mechanism are arranged in the crushing cavity, the primary grinding mechanism is formed by a first grinding roller and a second grinding roller, and the secondary grinding mechanism is formed by a third grinding roller, a fourth grinding roller and a fifth grinding roller; and the filtering mechanism includes two driving wheels and two driven wheels meshing with the two driving wheels through racks, a motor shaft penetrates through the centers of the two driving wheels to connect the two driving wheels into a who