Methods: 1. Salt is salty. 2. Dropping hydrochloric acid into the sample respectively, and generating sodium carbonate when gas is generated. 3. Sampling to prepare solution, and dropping acidified silver nitrate solution respectively. Salt is produced when there is white precipitation. Fourthly, it can be distinguished by observing the appearance: soda ash is white powder or white opaque fine particles, while salt is fine colorless transparent crystal particles.