Abstract: With the rapid increase of the train speed, aerodynamic effect has a more serious impact on the pressure load of the car body, and the trains crossing in the tunnel is more violent than that of a single train passing through the tunnel. In order to research the aerodynamic load of maglev train crossing in the tunnel, the one-dimensional unsteady compressible non-homentropic flow model method was adopted. The distribution characteristics of the maximum positive pressure, negative pressure and maximum pressure (maximum positive and negative pressure and maximum peak pressure) of the car body were analyzed and the influence characteristics of the tunnel length, speed and blocking ratio on the external pressure were researched. The results show that the maximum negative pressure value of the car body is much greater than the maximum positive pressure value during the train crossing in the tunnel; only when the tunnel length exceeds a certain value, would the maximum positive and negative pressure value of the car body appear in the head and tail train, respectively; the maximum pressure values of the head and tail cars remain constant after the tunnel length exceeds 2 km, and the maximum positive pressure values of the head and tail cars at different speeds basically coincide, which are close to “zero”; when the tunnel length is within a certain range, the maximum pressure is proportional to the square of the speed; and the maximum pressure increases linearly with the increase of the blocking ratio. The findings of this research can provide support for the car body aerodynamic fatigue strength design.