Underwater motion biological recognition and evaluation method based on multi-beam image sonar

The invention relates to the field of underwater organism monitoring and evaluation, in particular to an underwater motion organism recognition and evaluation method based on multi-beam image sonar. Comprising the following steps: S1, calibrating sonar data; s2, establishing a biological population acoustic standard library; s3, preprocessing a sonar image; s4, underwater moving target detection based on a Gaussian mixture model; s5, performing biological recognition and biomass evaluation; the method comprises the following steps: calibrating multi-beam sonar original data, and establishing a biological population acoustic intensity standard model library in combination with experimental data of biological populations with different densities; then applying the Gaussian mixture model to sonar image background modeling to realize underwater moving target detection and calculate the average acoustic intensity of the moving target; and finally, matching the detected moving target intensity with the biological p