The invention discloses a slope irrigation purifier. The slope irrigation purifier comprises a Yellow River water source, a primary water pump, a sedimentation tank, a sedimentation tank dirt discharging valve, a secondary water pump, an inclined pipe sedimentation tank, a tertiary water pump, a tertiary standby water pump, an inclined pipe sedimentation tank dirt discharging valve, a peak water pool, a peak pool dirt discharging valve, a backwashing filter, a pressure reducing valve, a high-slope regulating valve, a greening belt regulating valve and a water draining valve, the water outlet of the tertiary pump is connected with the peak water pool by a pipeline, the water outlet of the water reducing valve is connected with the water inlet pipeline of the high-slope regulating valve through an irrigation branch pipe to form a branch pipe water feeding pipeline, and the water outlet main pipe of the pressure reducing valve is connected with the water inlet of the greening belt regulating valve through an irrigation branch pipe to form a branch water pipe water feeding pipeline, and is also connected with the water inlet pipeline of the water draining valve. The automatic sedimentation, filtration and purification system of irrigation water is used in watering without artificial control, so compared with traditional artificial water spraying, the purifier has the advantages ofsaving of the use amount of water, economical property, good reliability, and saving of machines and manpower.