Artificial intelligence (AI) is attractive for safety critical fields. However, there have been few success cases, for the AI technique is usually lack of determinism and predictability, which is usually regarded as a disqualifier in a safety on text. Increased researches and supererogatory efforts are providing to incorporate AI into the safety-critical systems in recent years. In this paper, we present a scenario-based method for safety certification, with the method AI modules of system could be evaluated before invoked, if its trust ability is satisfied, then the program will be performed for safety critical systems, otherwise it will be terminated to ask human assistance or postpone the missions.