The invention discloses a pineapple automatic grading and sorting method and device based on binocular vision and multispectral detection technology. The method includes the following steps: firstly adopting the binocular vision system to detect the size and color maturity of pineapples, and grading the outer quality of pineapple; then adopting the multispectral detection to detect whether the inside of the pineapples is damaged or not, and detecting and judging the inner quality of pineapples according to the spectral curve characters of inner water content and carbohydrate content of normalpineapples and bad pineapples, and then grading the inner quality of pineapples; finally performing automatic grading and sorting of pineapples according to the above detection results. According to the method provided by the invention, pineapples can be accurately, efficiently and automatically graded and sorted, the algorithm is high in speed and few in operand, the device can be applied to mainengine equipment with poor configuration, is low in cost, and very suitable for field operation; the device is simple in structure, smaller in component size and convenient to operate.