The microscopic phase-field method was employed to study the antisite defect of Ni3Al which precipitated from high Al concentration Ni75AlxV25-x alloy. Result shows that the main antisite defect type of this alloy are VAl, NiAl; with the increasing of Al concentration, the AlNi antisite defect also increases; while changes of the other three types antisite defect NiAl, VAl, and VNi are slightly complex for its dependence on the precipitation or not of Ni3V phase; at comparatively lower Al concentration, when there is Ni3V phase, NiAl decrease with elevated Al concentration, while VNi increase and VAl keeps unconverted; at comparatively higher Al concentration, when there is no Ni3V phase precipitated from the matrix, NiAl slightly decreases with elevated Al concentration while VNi and VAl decrease sharply