With the increase of the replacement frequency of mobile phones, the recycling of used mobile phones (UMPs) has gradually become a hot topic. UMP recycling equipment based on the internet of things technology has become one type of the main devices to recycle UMPs, but there are still some problems such that low recognition success rates and tedious recycling steps. The key to solving these problems is to improve the accuracy of UMP recognition (UMPR). In view of the above problems, this paper reviews the methods of UMPR for UMP recycling equipment, which provides support for improving recycling efficiency. First, we briefly introduce the structure and recycling process of UMP recycling equipment. Next, the four typical methods of UMPR are addressed in detail and their respective shortcomings are analyzed. Then, these methods are summarized and analyzed, and the shortcomings and deficiencies of the current UMPR methods based on artificial intelligence, especially the image recognition method are addressed. Finally, the directions for future research on UMPR are given out.