The decentralized operation control system (DOCS), which realizes the function of operation command and safety protection to high-speed maglev train, is a kind of safety-critical computer control system. On the basis of the experience of developing, debugging and running DOCS engineering prototype, using for 1.5 km high-speed maglev experimental railway line, an index system for evaluating the credibility of high-speed maglev DOCS was set up. Based on the Analytic Hierarchy Process (AHP), a credibility evaluation method and process for the DOCS were proposed, and by using verification, validation and accreditation technology, the comprehensive analysis of the DOCS credibility evaluation index was carried on. At last, the credibility index, which is useful to nationalized high-speed maglev DOCS, was obtained.