In this paper, the abnormal state （the raising of the flow stress） , which appears in the process of the die cavity being formed by use of through Zn-Al super-plasticity alloy, has been studied from origined structure. Rusults show that, there are abnormal net structure. Authors have tried to find a suitable heat treatment method to eliminate it, and made compared tests at isothermal compression for the samples before and after elimination of the net structure.