The invention relates to a device with an automatic replacement function. The device comprises a U-shaped assembling frame, four mirror frames are arranged on the U-shaped assembling frame, and two lenses are fixedly arranged in the middle of each mirror frame; and bumps are fixedly mounted at the left and right ends of each mirror frame, and composite grooves for slidably arranging the bumps in aone-to-one corresponding manner are formed in the left and right ends of the assembling frame. A motor is arranged at the right end of the assembling frame, and is respectively connected with an incomplete gear 1 and an incomplete gear 2; the incomplete gear 1 is meshed with a rack 1 and the incomplete gear 2 is meshed with a rack 2; and pushing plates are arranged at the lower end of the rack 1and the front end of the rack 2 in a welding manner. The device has the high degree of automation, and can automatically replace various lenses in sequence through the restricted sliding of the composite grooves, so that not only can the tedious work of manual replacement of glasses be reduced, but also eyes can be indirectly protected.