The invention belongs to the technical field of biological monitoring environment, and specifically relates to a shellfish monitoring method for ocean oil spill pollution. The shellfish monitoring method comprises the steps of utilizing typical bivalve mollusk such as short-necked clam and chlamys farreri in China to determine the shellfish visceral mass autioxidant enzyme activities including superoxide dismutase, glutathione glutathione S-transferase, peroxidase, glutathione peroxidase and catalase activity, integrating the enzyme activities so as to form an integration biomarker responding index (IBR), establishing a dose-effect relationship between the IBNNR and petroleum concentration, adopting a one-dimensional variance components method (ANOVA) to carry out notable difference analysis, determining the forcing degree of petroleum pollution on organisms, and finally judging pollution level of the ocean oil spill.