As a vital resource for the survival and development of enterprises, large customers have become the main battlefield of competition among enterprises. Today, under the impact of VUCA, the long sales process, complicated interpersonal relationships, uncontrollable competitors, and tangled benefits distribution... all make key customer sales increasingly difficult. Therefore, it is particularly important to see clearly the needs and situations of customers, how to use simple and clear methods and tools to promote the sales process, and how to respond to changes in the sales process with the correct strategies and ideas.