The present disclosure belongs to the field of offshore oil, and in particular relates to a method for assessing the safety integrity level of offshore oil well control equipment. The method for assessing the safety integrity level of the offshore oil well control equipment comprises three major steps: creating a safety instrumented function evaluation module and dividing the related devices for performing the safety instrumented functions into a sensor subsystem; a controller subsystem and an actuator subsystem, establishing a dynamic Bayesian network model for respective subsystems for calculation; and integrating, analyzing and optimizing the safety integrity data of the subsystems.