Abstract: L gas field in South China Sea is an offshore deep-water high-yield gas field, whose reservoirs are fine siltstones with high porosity and high permeability. The vertical range of reservoir physical properties changes greatly, some horizons have strong heterogeneity, and the particle size and shale content change greatly. There are often inconsistent design results in the selection of sand control modes and sand retaining accuracy by conventional methods.The high cost of offshore deepwater gas field development determines that its sand control measures must be reliable, so it is necessary to further verify and optimize sand control parameters with the help of experimental means. Fine siltstones of HL Formation in L deep-water gas field are selected as the experimental object to simulate the formation sand. Under the same gas production displacement conditions, the comparative experiments of sand control effects of different sand control methods, different sand control accuracy, different displacement time, different gravel packing thickness and different sand retaining media are carried out. The comprehensive evaluation is carried out from two aspects of the overflow capacity and the sand retaining effect. It is determined that the use of 120 μm screens to pack 20/40 mesh gravel in this gas field is more advantageous, and the thickness of the packing layer is at least 1.5 inch. The evaluation scheme has certain popularization and application value.