Effects of pre-furnace pouring temperature on the size and rate of shrinkage porosities and cavities during the production of investment casting stainless steel parts were analyzed. The modification of pouring temperature was added to Henkin formula to calculate the inner gate modulus, and the actual inner gate modulus was obtained, which was verified to be reasonable. Reasonable pouring temperature was determined, and the empirical data of pouring temperature for reducing shrinkage porositie and cavities were presented.