The utility model discloses a novel choice class production line of carrot machine vision, whole production line include computer vision part, automatic control subtotal mechanical device part, and wherein mechanical device mainly comprises even fruit machine, conveyer, lamp house and hierarchical mouthful of four parts, and conveyer wherein divide into the three section. Arrive on the even fruit machine on passing through the material loading machine after the carrot is washd, even fruit machine with the carrot one -way pave even, and through slowly falling on the ware places first section low -speed conveyer with the carrot order, through second festival conveyer with higher speed, the carrot is fast through the lamp house passageway, form images through the mirror surface, the linear array camera acquires the image of three side and transferes the computer, the computer provides corresponding grade information through image processing, and then the terminal high -speed air -operated solenoid valve of control third festival conveyer, blow the carrot in hierarchical mouthful that penetrates the different brackets, realized that the full automatic of carrot is choice hierarchical.