In pre-production period of Dafaping Gravel Processing System of the Longtan Hydropower Station, after a number of issues being found through quality inspection, the production technology and equipment were debugged and improved. By summarizing the Longtan Project aggregate preduction process, the sand blowing machine to? improve the stone powder content in RCC was adopted, and for strengthening the force of water washing of the first screening, the water washing system of the secondary screening was set up. Controlling quality standard of wrapped powder is presented on the basis of the reason caused by the aggregates being wrapped with powder. In order to control the qualified rates of oversize and midsize screened-remainder of aggregates, the coarse aggregate equipment is improved, through which aggregates can be slowly fallen down, and the produced material is permitted to remain a certain content of oversize aggregates. The test results prove that the improved aggregate system, quantitatively and qualitatively, can completely satisfy the Longtan Hydropower Station dam construction requirements.