Objective (1) To determine the feasibility of using fluid-structure coupled ALE(Arbitrary Lagrangian– Eulerian) method in javelin flight simulation; (2) To determine the attacking angle in the optimum thrust by ALE method. Methods A FEM model of both javelin and air was built by Femb pre-processing software; and materials and elements properties were set up. Based on the applied loads, initial and boundary conditions, the simulation was carried out for given release parameters using LS-DYNSA solver. Results The vertical and horizontal displacement of javelin tip were obtained at 30m/s release speed, 39 degree release angle and 2 meters’ height. Conclusion It is feasible to simulate javelin flight using ALE method; and the adjustment of release parameters in simulation can be controlled easily. The attacking angle is -3°obtained for the optimum throwing distance at 30m/s and 39 degree.