The invention relates to the technical field of image collection and recognition, and specifically relates to an automatic measurement method for morphological parameters of a prawn based on image recognition and a cascade classifier. The automatic measurement method comprises the steps of S1, collecting a plurality of prawn color images to serve as samples; S2, training the samples, and then classifying the trained samples to obtain an LBP feature based cascade strong classifier; S3, collecting a prawn color image A to be measured, and performing normalization correction on the prawn color image A to obtain a normalized image B; S4, performing image segmentation on the normalized image to obtain a segmented image B; S5, performing ruler measurement on a segmented image C obtained in the step S4 to obtain a measurement image D; S6, performing image correction on the measurement image D obtained in the step S5 to obtain a corrected image E; and S7, recognizing the corrected image E by using the cascade strong classifier, and calculating morphological parameters of the prawn to be measured. According to the algorithm, accurate measurement for the morphological parameters of the prawncan be accurately implemented, and the measurement accuracy and the measurement efficiency can be improved.