In critical psychology, the sandwich effect is a phenomenon in which people sandwiched the content of the criticism between two praises so that the critic can accept the criticism happily。This phenomenon is like a sandwich, the first layer always agrees with, appreciates, affirms, and cares about the advantages or positive aspects of the other person, the middle layer is filled with suggestions, criticism or different opinions, and the third layer is always encouraging, hoping, trusting, supporting and helping, which makes the next taste endless。For example: today's soup is really delicious, just a little salty, next time light, I can drink three bowls in a row。