A handle assembly and a stapler including the same are provided. The handle assembly includes: a first handle component and a second handle, a first end of which is rotatably connected with the first handle component. The handle can be divided into a first handle component and a second handle, and a linkage state of the first handle component and the second handle can be controlled by a moving position of a slider which can be returned by action of a compression spring after the slider is free from a force exerted by the indicator, and a position of the compression spring is defined by a first limiting structure of the slider and a second limiting structure of the first handle component.