The invention discloses precise investment casting powder and an investment casting and moulding process using the same. The precise investment casting powder comprises the following raw materials in percentage by weight: 25 to 35 percent of alpha semi-hydrated gypsum powder and 65 to 75 percent of quartz powder. After the two raw materials are mixed, based on the weight of the mixture, 0.2 to 0.6 part of superplastieizer, 0.1 to 0.3 part of water reducing agent and 0.2 to 0.5 part of antifoaming agent are added into 100 parts of the mixture. The materials are uniformly mixed to form the finished product, namely the precise investment casting powder. The investment casting and moulding process comprises the following steps: according to the precise investment casting powder prepared from the raw materials, adding 38 to 40 percent of water into 100 percent of the precise investment casting powder, stirring the mixture to form paste, pumping air out of the paste, pouring the paste into a mould to perform vacuum treatment moulding, solidification and baking at a high temperature, and casting the molten metal to cast a cast product or store the molten metal for later use.