Short-acting insulins, also known as regular insulins, include human short-acting insulins and animal short-acting insulin preparations. Fast-acting insulins, also known as ultra-short-acting insulins, both need to be injected subcutaneously before meals to control post-prandial blood sugar at the next meal, and both need to be combined with basal insulin. The difference between short-acting insulin and rapid-acting insulin mainly includes the following points: 1. The structure is different, short-acting insulin has the same molecular structure as human insulin. The amino acid sequence is changed according to the different types of rapid-acting insulin, so the full name of rapid-acting insulin is rapid-acting insulin analogue. 2. onset and duration of action, short-acting insulin takes effect 30 minutes after subcutaneous injection, reaches the peak effect in 2 hours and lasts 4-6 hours. Fast-acting insulin takes effect 5-10 minutes after subcutaneous injection, reaches its peak effect in 1 hour, and lasts 2-4 hours. Therefore, compared with short-acting insulin, rapid-acting insulin has faster onset and shorter peak time, which can effectively reduce the incidence of pre-meal hypoglycemia in the next meal.3. Injection time, short-acting insulin is injected subcutaneously 20-30 minutes before a meal. Rapid-acting insulin is more flexible, and can be injected subcutaneously before, during, or even immediately after a meal.