Molluscan shells lived in harmony with nature upon the combination of multiple factors, e.g., surface morphologies, multilevel structures and component materials, and achieved an optimum adaptation to the surroundings based on such biological coupling functions. The Polyplacophora usually has complex surface topography and specific living behaviors which showed exceptional anti erosion property. Thus, the chiton Acanthochiton rubrolineatus was selected to study its bionic anti erosion mechanism. According to biological coupling and bionic anti erosion property of chiton, the explicit dynamic software ANSYS/LS-DYNA was used to simulate the erosive process of uni bionic model of configuration and configuration groove/convex morphology dual bionic coupled model imitating the shell surface of chiton. The mechanism of erosion of each model was comparatively analyzed. The overall erosion resistance of the three models was sorted as convex curved plate, groove curved plate and smooth curved plate. However, in the peak of the curved plate, the stress dispersion effect of groove was much better than that of convex, whereas the stress dispersion effect of convex was better than that of groove at the pterion region. The simulation results indicated that the shell plate of chiton evolved an optimum combination of morphologies with thick riblets distributed in the peak (grooves were formed between the riblets) and convexes scattered around the pterion region, and thus the chition was endowed with exceptional anti erosion property. The current research result could be further used in the series of agricultural irrigation machinery, such as water pump, turbine pump, spray irrigation equipment and drip irrigation system.