Spray etching machine and FeCl₃-based etchant were used to process the die steel . The influence of two independent factors, etchant temperature and spray pressure were investigated, specifically on the etching depth. The trend of etching depth was obtained with experimental analysis. Via experiments it is found that the growth rate of etching depth is increased with the rise of the etchant temperature. However, the growth rate of etching depth first increases and then decreases gradually with the increase of the spray pressure. The factors that contribute to this change of etching depth were analyzed.