For the sand embankment water loss and soil erosion prevention situation,a model of sand soil surface anti erosion test was established to carry out rainfall scouring test. Based on the model test,anti-washout performance of different sand embankment slope protection layer was studied and erosion process of protection layer was analyzed. It is concluded that the mixture of sandy soil,bentonite and straw can resist rain erosion,ensure the smooth growth of plant seeds and facilitate construction.