Self-raising flour is a mixture of flour and food additives, which is made of wheat flour and pre-mixed with leavening agent. The leavening agent in self-raising flour is a kind of food additive, also known as bulking agent. This additive is mixed with flour, water and other ingredients when kneading dough, and after fermentation, it can generate gas, thus making the dough swell and become soft. The convenience of self-raising flour lies in that it can be used to make various flour products, such as steamed bread, steamed stuffed bun, fried dough sticks, etc., just by adding a proper amount of water or other ingredients to flour. Because self-raising flour contains leavening agent, it is not suitable for making dumplings and noodles, because these products need to maintain the integrity of gluten in the process of making, and leavening agent will destroy the structure of gluten, resulting in easy cracking or breaking of products.