The invention discloses a pearl detection device with an automatic sorting function. The pear detection device comprises a base, wherein four supporting plates are arranged on the upper side wall of the base, the upper ends of two of the four supporting plates are jointly connected with a placement box, the upper side wall of the placement box is fixedly connected with a connecting plate, the upper end of the connecting plate is fixedly connected with a cleaning plate, a plurality of through holes are formed in the upper side wall of the cleaning plate, a plurality of pearls are arranged on the upper side wall of the cleaning plate, and the upper side wall of the cleaning plate is connected with a push plate in a sliding mode. According to the pearl detection device, the pearls are washedand then detected, so that the color detection results of the pearls are prevented from being influenced by impurities, intermittent falling of the to-be-detected pearls is realized through intermittent clamping of a wedge-shaped block and a wedge-shaped groove, then sequential detection of the color of the pearls is completed, and sorting between the high-quality pears and the pears with the poorquality is achieved through the connection between an S9702-RGB color sensor and an STM32 microcontroller, so that manual sorting is avoided, the working efficiency of the pearl sorting is improved,the sorting quality is high, convenience and practicability are achieved, and the popularization is high.