Not the same.

1. Different ingredients. Starch is a high-molecular carbohydrate, a polysaccharide polymerized from glucose molecules; sweet potato powder is a powder made from sweet potato starch, etc., and is granular, with two types: coarse and fine.

2. The applications are different. Starch is usually widely used. In daily life, we can use it to make noodles, steamed buns, pastries, etc.; while sweet potato starch is mainly used to make Chinese snacks, such as mountain flour dumplings.