At present, there are many reported peptide condensers, but they have great influence. The widely used condensers are mainly divided into carbodiimide type, phosphorus positive ion type and urea positive ion type from the perspective of molecular structure. Among them, phosphorus positive ion and urea positive ion type condensers have the best performance. China Reagent Network provides dozens of high-purity condensing agent products, such as DIC, AOP, HOBt, HOAt, etc., which can participate in the reaction under mild conditions. The reaction speed is fast, the product racemization is small, and the yield is high. It meets the needs of "atomic economy". The domestic stock is sufficient and the batch quality is stable. It has been used by many production enterprises and scientific research institutions.