[Objective] The effects of contour reverse-slope steps on the water use efficiency and yield of maize crops in sloping land were explored in order to provide scientific basis for crop cultivation in sloping land in Yunnan Province.[Methods] Maize (Yunrui 668) was used as test material. Two sloping farmland plots with contour reverse-slope (2^# and 3^#, CR) and 1 undisturbed control plot (1^#, CK) were set up in the field experiment. The maize growth index, net photosynthetic rate, transpiration rate, water use efficiency and crop yield were measured by field monitoring method to investigate the effects of contour reverse-slope order on maize growth and photosynthetic characteristics.[Results] The effect of contour reverse-slope measure on the ear height of maize and stem diameter was not significan, while the promotion effect on the height of maize plant was the most significant, with an increase of 27.9%. The leaf area index (LAI) of the contour reverse-slope sample plot was significantly higher than that of the undisturbed slope land, with LAI as high as 5.01~5.78. After the grouting stage, relatively high LAI could be maintained, while the LAI of the CK group was ranged from 3.78 to 4.79, which decreased rapidly. The net photosynthetic rate, stomatal conductance, WUE_L (instantaneous water use efficiency) and water use efficiency of maize leaves under the contour reverse-slope was higher than that of sloping land. Maize yield increased by 9.6% and 13.8%, respectively, compared with sloping farm land.[Conclusion] In the slope cultivated land area in Yunnan Province, by increasing soil moisture and soil water storage, the contour reverse-slope measure can promote photosynthesis of leaves and physiological status, which lays a physiological foundation for dry matter production of maize and improves the crop yield. Under the condition of natural rainfall, when the slope was 15°, the contour reverse-slope measure has the best promotion effect on WUE of photosynthetic characteristics and yield promotion of maize.