Abstract: We investigate the effect of crosswinds on the unsteady aerodynamic forces of moving trains. Two methods are introduced to simulate the fluctuating wind velocity at the position of a moving vehicle. Using the quasi-steady theory and aerodynamic weighting function approach, a calculation formula of the unsteady forces on moving trains is established by considering the nature of different turbulent components and various wind directions. A numerical example is given to explore the effect of different parameters on the simulated results. The results show that the filtering and time-lag effects are observed in the weighting function approach. As additional wind turbulences from different directions are considered, there are greater fluctuations in the force. The mean value and coefficient of variance of the unsteady forces are affected by the various wind directions and lateral turbulences, respectively.