In software development, it is a common requirement to handle behavior changes when an object changes state. In order to avoid using complex conditional judgments in the code, the State Pattern provides an elegant solution. Through the State Pattern, we can encapsulate the behaviors of different states into independent state classes, making state management clearer and more flexible. This article will explore the concept of the State Pattern, the difference from other patterns, the problems it solves, implementation examples in Golang, and practical applications of the State Pattern.