The invention discloses a water saving ditch construction method for a sand land, and belongs to the technical field of agriculture. The method comprises the following steps: selecting a land, paying off, digging a water saving ditch, drilling permeation holes in soil on two sides of the water saving ditch, paving an isolation layer in the water saving ditch, digging a collecting gutter and a water storage pool, paving filter plates in the water saving ditch and the collecting gutter, finishing surface soil on two sides of the water saving ditch, and mulching films on the surface soil on two sides of the water saving ditch. According to the water saving ditch construction method, rainwater can be collected, and water permeated from the soil can be still collected; by the horizontal permeation holes, the salt content of the sand land is reduced; the bottom of the water saving ditch is mechanically reinforced, and the top of the water saving ditch adopts a slope, so that the stability of the water saving ditch is guaranteed; the filter plates and a non-woven filter material are paved on the water saving ditch, so that water can be filtered, direct solar radiation can be reduced, and evaporation can be reduced; the filter plates are covered with wheat straws, so that water evaporation is reduced, scouring to the water saving ditch due to the rainwater can be reduced, and the stability of the water saving ditch is guaranteed; and the slope is covered with a film, so that water evaporation can be reduced, and water retention, fertilizer retention and temperature rise are facilitated.