The invention discloses a crankshaft water conservancy irrigation device. The crankshaft water conservancy irrigation device comprises a bottom plate, a mixing tank, a first cylinder block, a first piston, a first piston rod, a second cylinder block, a second piston, a second piston rod, a motor, a first sleeve, a second sleeve, a rack, a gear, a second rotating shaft and a nozzle. By arrangementof a motor, a crankshaft, the first cylinder block, the first piston and the first piston rod, intermittent discharging and grinding are realized through cooperation, grinding efficiency is improved,pesticides or fertilizers are easily soluble in water, and the utilization rate is increased. By arrangement of the second cylinder block, the second piston and the second piston rod, continuous waterspraying of the nozzle is realized through cooperation. By arrangement of the second sleeve, a third connecting rod, the rack, the gear and the second rotating shaft, the second sleeve drives the rack to move bilaterally through the third connecting rod, the rack drives the second rotating shaft to rotate forwards and reversely through the gear, and the second rotating shaft drives the nozzle torotate forwards and reversely, so that a spraying range is expanded, completeness and uniformity in spraying are improved, and irrigation efficiency is improved.