The eastern South China Sea is mainly composed of loose sandstone reservoirs with high wax content and serious sand production. Frac-packing is often used as an integrated measure for sand control and production. Embedding of proppant and migration of formation sand influent the fracture conductivity, which nevertheless are not considered in existing fracture design methods. To resolve this issue, a new proppant index method was proposed that considers proppant embedding and formation sand migration. The proposed method was applied in a case study for a well in the eastern South China Sea, when the proppant volume is set to from 20 m³ to 30 m³, the fracture width optimized by the traditional proppant index method is at the range of from 2.2 cm to 2.7 cm, and the fracture length is from 18.0 m to 22.0 m. When considering particle migration and proppant embedding, the optimized fracture width by the new method is at the range of from 3.5 cm to 4.2 cm, and the optimized fracture length is from 11.6 m to 14.2 m. The deeper the sand migration and proppant embedding, the optimized fracture length decreases and the optimized fracture width increases. The new method considers the influence of formation sand migration and proppant embedding, which has certain guiding significance for the design of reservoir frac-packing process parameters.