Basis on the surface morphology of carbon fiber and viscosity characteristicstwo epoxy resin,the appropriate curing pressures have been defined.The expansion pressure design and curing process parameters was compared between the two epoxy resin with different viscosity.The results demonstrate that the epoxy resin with high viscosity has an obviously optimized manufacturability and shorten the curing cycle by 13.6%.The gel pressure design temperature（135±5） ℃ can guarantee the internal quality of the product，the curing temperature（170±5） ℃ reduces the risk of product deformation.The defect proportion of composites supporting beams can be controlled below 0.5%,implemented the quality requirement for aerospace structure composites.