Self-compacting concrete（SCC） is regarded as a two-phase suspension system consisting of coarse aggregate and mortar. Four groups of basic mortars prepared by crushed sand were designed to prepare SCC， which had eight mortar film thicknesses ranging from 1.5 mm to 2.9 mm. The effects of the mortar rheological properties， strength and film thickness on the workability and mechanical properties of the SCC were investigated. The performance prediction formulas for SCC based on mortar properties （initial yield shear stress of the fresh mortar and strength of the hardened mortar） and film thicknesses were established. The results show that to ensure the workability and mechanical properties of the SCC incorporated with crushed sand， the optimized mortar film thickness ranges from 1.9 mm to 2.3 mm， corresponding to a basic mortar maximum initial yield stress range from 51.9 Pa to 65.2 Pa； the predictive formulas exhibit significant correlation， with correlation coefficients exceeding 0.90.