The invention discloses a novel synthesis method for 2-amino vidarabine. According to the method, the target product with the overall yield of 61% is prepared from vidarabine, which serves as a raw material, through 3 step reactions, i.e., perbenzoylation reaction, nitration reaction and ammonolysis reaction. A first advantage of the method is that the prepared 2-amino vidarabine is of beta conformation completely, so that the tedious step of isomer separation in the traditional method is avoided. A second advantage of the method is that the used raw materials are cheap and readily available, and other reagents are all common chemical raw materials and are wide in source. A third advantage of the method is that the number of steps is small, the operation is simple and convenient, and the whole process does not need column chromatographic separation, so that industrialized and expanded production is facilitated.