Abstract: Abstract: To study the protective effect of the combat helmet against traumatic brain injury induced by blast wave, an anti-explosion test was carried out for 50g TNT from the head model with and without helmet protection at 1m. The frontal, parietal and posterior cranial blast wave overpressure of the head model with and without helmet protection were compared and analyzed. The finite element model of the head with typical cranial structure was established and the blast wave loading was carried out to simulate the test conditions. The validity of the simulation model was verified by the test results. At the same time, the variation rule of the blast wave flow field under different conditions was analyzed by numerical simulation. The effect of foam liner on helmet protection capability was studied by numerical simulation. The results show that the typical combat helmet can attenuate the frontal air overpressure to 54.5% of that without protection, but can enhance the posterior cranial air overpressure to 2.19 times that without protection, which harms the protection of posterior cranial. The foam padding in helmet suspension can reduce the negative effect of the helmet on cranial posterior protection and improve the protective ability of the helmet against blast wave.