In order to calculate the fatigue reliability of tower crane under random dynamic loads, this paper consider the distribution of the input parameters affect the tower crane reliability, such as distribution of maneuver load parameters, using stochastic finite element method to calculate stress-time history of tower crane fatigue check points, using rain flow counting method to get the load spectrum of the check points, the residual strength is calculated based on Miner linear fatigue cumulative damage theory. Considering the complexity of the structure of tower crane, it is unable to get the explicit expression of the reliability function. Based on stress-strength interference theory, this paper uses stochastic finite element method to calculate the tower crane reliability, and. the influence of overload on reliability is analyzed quantitatively. The results show that with the use of tower crane, its reliability decreased gradually and due to the cumulative fatigue damage there is a sharp decline of the reliability after a certain period of time, and overload has a great effect to the tower crane reliability. Due to the distribution of all input parameters influence the reliability of the tower crane were considered, and all possible conditions in the work of the tower crane were simulated, the results are more consistent with the actual than existing methods, which can provide reference for the evaluation of fatigue reliability of tower crane.