The fatigue reliability of light-wharf structures which are affected by wave loads and ship impact forces is studied by wave spectrum analysis theory and the theory of linear cumulative damage. Based on the large displacements characteristics of light-wharf structures, we calculate the impact forces under consideration of the light-wharf’s stiffness. The wave load is calculated by the Airy Wave Theory and the speed of water particles is calculated by the linear Morison Equation. The results show that the wave loads and impact forces have remarkable effects on the fatigue reliability of light-wharf structures, and the combined effect of wave loads and impact forces should be considered when calculating the fatigue life.