Disclosed herein are a screen protector assembly, a screen protector applying assembly and a screen protector applicator. The screen protector assembly comprises a screen protector layer, a retention layer and a first matching member. The retention layer is bonded to the screen protector layer. The first matching member is fixedly connected to the retention layer, and the first matching member is used to be detachably connected to a protector applying assembly. With the above arrangement, a detachable connection between the retention layer of the screen protector assembly and the protector applying assembly is realized, allowing the retention layer to be detached from the protector applying assembly after a protector is applied to a screen, thereby allowing the protector applying assembly to be reused, and saving costs.