The invention discloses high-performance concrete prepared by adopting rice hull ash, silicon ash and graphene oxide as admixtures and a preparation method thereof. The concrete per cubic meter comprises, by weight, 600-720 parts of cement, 50-100 parts of admixtures, 850-1,000 parts of coarse aggregate, 550-650 parts of fine aggregate, 90-130 parts of water and 13-25 parts of water reducing agent, wherein the admixtures are composed of the rice hull ash, silicon ash and graphene oxide according to the mass ratio of (2-10):(2-10):(0.001-0.01). According to the high-performance concrete, the rice hull ash, silicon ash and graphene oxide are adopted as the admixtures, the raw materials of the three kinds of admixtures are mutually activated, the early and later strength of the concrete can be improved, microscopic cracks of the concrete can also be effectively avoided, and the working performance and mechanical properties of the concrete can be improved. Meanwhile, the adopted admixturesrelieve the pressure of the high-strength concrete on supplying silicon ash and superfine slag powder, the utilization rate of the agricultural waste such as the rice hull as is also increased, and the requirement of sustainable development is met.