Ship unloader crane was widely used in transportation, and uploaded or unloaded cargoes from ships, which could influence efficiency and benefits of transportation greatly. In order to improve the reliability and safety, and decrease its risk in working flow, a method of fatigue life assessment was proposed in this paper. According to related standards and properties of risk, finite element method and experimental stress analysis were integrated to assess the working condition of a ship unloader crane. Finite element models of primary structures subjected to loads were built to achieve dynamic properties, which could supply a basic reference to experiment and guidance to locate the tested positions. Afterwards, wireless dynamic resistance strain-gauges were adopted to execute static and dynamic stress, and the tested results combined with finite element analysis were applied to strength analysis. Based on nominal stress and Miner principle, rainflow method was developed to fatigue life assessment of this ship unloader crane. The final results indicated that residual life of this crane was 4.67 years.