Quantitative numerical simulation of three-dimensional dendritic growth in pure undercooled melt is carried out based on phase-field model of thin-interface limit and incorporating interfacial energy anisotropy which is solved by an accelerated algorithm of the dynamic computing regions, the dendritic growth is faithfully described. The dendritic tip is analyzed by cutaway view, indicating that the anisotropy of main branches’ section is not more obvious than that of main branches. The dendritic tip growth speed, tip radius, tip Peclet number as well as classic stability parameter σ* are simulated, compared with reported values under same condition,and they agree well with each other. Dendritic growth law that is in accordance with crystalline theroy is achieved, and it is proved that it is feasible and effective to simulate three-dimensional dendritic growth using phase-field method.