A fertilizer crushing device for the agriculture comprises a bottom plate, a supporting plate, a recycling device, air cylinder devices and material guiding devices. The bottom plate is provided with first supporting blocks and first wheels. The supporting plate is provided with a first through hole, a blockage block, a first connecting rod, a holding rod, a first support, a second wheel, first crushing teeth, a third wheel and second crushing teeth. The recycling device comprises a recycling box, first supporting rods, first positioning blocks, second supporting rods, first cross rods, first vertical rods and first springs. Each air cylinder device comprises an air cylinder, a push rod, a second support, a push plate, a vertical plate, a second vertical rod and a third vertical rod. Each material guiding device comprises a fourth vertical rod, a second cross rod, a second spring, a third support, a third spring, a material guiding block, a limiting block and a fourth support. According to the fertilizer crushing device, fertilizer can be thoroughly crushed, so that the labor amount of manual work is reduced, and the labor intensity of manual work is relieved.