In order to optimize the casting methods of zinc alloy, which was the replacement of copper alloy materials in the future, we tried our best to improve the solidified form and mechanical properties of zinc alloy casting quality. From the experimental conditions on the existing basis, in the zinc alloy solidifying process, the pressure values ranging from 0.1 ~ 1.0Mpa nitrogen stress management were carried out on alloy solidification .After the cooling ,we had the casting sample comparison macro observed and tensile experimental data analyzed. The results showed that: when the pressure was increased to 1.0Mpa, the macro-organization of the zinc alloy achieved the best, and the degree of shrinkage and pores on the outer surface of the metal were smallest. The mold surface was more smooth, and the number of stomata reduced . The quality of the internal organization could be preliminarily judged by the analysis and observation on the zinc alloy appearance.