[Objective] The effects of sand cover thickness， rainfall intensity， and slope on the formation of water flow， sediment yield， moisture change， and slip in a binary sand and soil structure on loess slopes were analyzed to inform the control and prevention of soil erosion in the wind-water complex erosion area. [Methods] Quantitative analysis was conducted based on laboratory rainfall simulation experiments， through which the processes of runoff， sediment production， erosion， and sliding， as well as spatiotemporal variations in water content on sand-covered loess slopes， were investigated. [Results] ① Sliding phenomena on sand-covered loess slopes were more likely to occur under prolonged rainfall. Moreover， the time of sliding occurrence was delayed on slopes with thicker sand cover， whereas increased rainfall intensity and steeper slopes accelerated sliding. Sediment yield from sliding increased with higher rainfall intensity and steeper slope. ② The variation rate of soil water storage was collectively influenced by sand thickness， rainfall intensity， and slope gradient， and increases significantly with an increase in these three factors. ③ The variation in sand saturation could be divided into three stages： rapid increase， stable state， and renewed growth. ④ Variations in soil saturation indicated that the critical conditions for sliding were influenced by sand thickness， rainfall intensity， and slope gradient. [Conclusion] Sliding on sand-covered loess slopes is substantially influenced by soil saturation， which is controlled by sand thickness， rainfall intensity， and slope gradient.