In order to seek the windbreak and sand fixation of aeolian sandy soil in Horqin sandy land，at the same time，quickly establish vegetation to promote sand fixation，field experiments were conducted to study the effects of spraying clear water (CK)，straw granule slurry (PS)，clay slurry (CM) and mixed slurry of straw granule and clay (40%PS +60%CM) on the formation and maintenance of sandy soil crust，organic carbon content and its components，exchangeable cations and soil aggregates，and the effects of Pennisetum grass seeds added with straw particles and clay mixed pulp on the growth of Pennisetum. The results showed that the crust formed by spraying straw particles and clay slurry on the surface of sandy soil within one year maintained the stability of sandy surface. On the 60th day，compared with CK treatment，the soil moisture content of mixed crust formed by 40%PS+60%CM treatment increased by 7.26%. Compared with PS and CM treatments，the crust thickness increased by 44.00%-56.00%，and the soil compactness increased by 146.37%-283.16%. On the 300th day of the experiment，compared with CK，40%PS+60%CM treatment significantly increased the soil organic carbon content by 824.43%(P<0.05)，and increased the contents of humus and humic acid. Compared with CK treatment，mixed crust and clay crust increased the exchangeable calcium ion content by 48.20%-120.66%. Compared with CK treatment，mixed crust increased the proportion of aggregates with particle size less than 53μm by 887.91%. Redundancy analysis showed that the proportion of clay particles smaller than 53μm was a vital factor affecting the content of humus and humic acid. The mixed crust of straw particles and clay regulated aggregates and cations to realize the accumulation of organic carbon in sandy soil. The formation of mixed crust of straw particles and clay increased the aboveground dry weight of Pennisetum by 315.38%-484.62%. To sum up，the crust formed by spraying the mixed slurry of straw particles and clay minerals in Horqin sandy land lasted for a long time，and at the same time，the crust increased the content of organic carbon and humus in sandy soil，which could reduce the loss of fine particles in aeolian sandy soil，promote plant growth and achieve the purpose of effectively fixing sand and carbon.