Starting with the definition of wartime equipment maintenance support effectiveness, deeply analyses the difference between equipment maintenance support effectiveness and equipment maintenance support capability. Based on Bayesian network theory and experts experience knowledge in the field of equipment maintenance, an evaluation model of wartime equipment maintenance and support effectiveness is established, which takes equipment command efficiency, equipment maintenance efficiency, and supply efficiency as main evaluation indicators. Based on Netica software, the Bayesian network for evaluating the effectiveness of wartime equipment maintenance support is constructed. The gradient descent method is used to learn network parameters. Finally, the feasibility of the model is proved by a practical case.