Abstract: Iron foil is the important target material for the experimental research of state equation. Its micro structure has great influence on the quality of target and the results of physics experiment. The cold rolled iron foil was selected as raw material which was used in the preparation of target. It was hot-pressed at different temperatures in vacuum for 60 min first. And then, microcrystalline size, strain, grain size, preferential orientation and residual stress of these samples were measured and characterized. Based on it, the trends of the above parameters were analyzed. Furthermore the evolution process of micro-structure was discussed. The results indicate that the samples undergo recovery, recrystallization and grain growth sequentially with the increase of temperature. The recovery is the predominant mechanism at the temperature below 550 ℃. In this stage, microcrystalline grows up, the residual stress decreases, and the shape and preferential orientation keep stable. When the temperature exceeds 550 ℃, the recrystallization completes and the samples enter into the stage of grain growth. The micrometer-sized equiaxed grains replace the fibrous tissue in the original sample, and its preferential orientation obviously transforms. The abnormal grain growth phenomenon does not appear in all samples.