In order to investigate the performance of high performance concrete compounded by fly ash composite powder under low water-cement ratio (0.20),the paper discovered through mechanical property and microstructure analysis that the strength of fly ash concrete is low in early period but high in late period.The strength of slag micro powder concrete can rapidly increase in early phase.The strength of concrete is obvious when two complementary complex mixed. The work performance is better and meets the requirements of pumping concrete when fly ash, slag single blending and composite admixture. The Ca(OH)2 produced by surface-active of SiO2 and Al2O3 of particle and cement can occur volcano ashes reaction and create C-S-H gel that can reduce Ca(OH)2 in the concrete interface region.pozzolan cement produced in a slurry,Refinement and reduction of concrete.The unhydrated particles can be filled with concrete and significantly improve the density of concrete, reduce calcium silicon ratio of concrete.