铁路货场的装卸机械以门式起重机为主，对这些设备进行一次可靠性评估具有重要的意义。本文介绍铁路门式起重机金属结构、机械与电气部分的故障分布规律；并按照无故障性指标、维修性指标和有效性指标三部分分别提出其计算公式。最后根据北京、上海与成都的设备调查列出了它们的可靠性指标。 The loading and unloading machinery of railway freight yard mainly adopts gantry cranes. It is of great significance to evaluate the reliability of these equipments once. This paper introduces the fault distribution rules of the metal structure, mechanical and electrical parts of the railway gantry crane. According to the three parts of the fault-free index, the maintenance index and the validity index, the formulas are respectively proposed. Finally, according to Beijing, Shanghai and Chengdu equipment survey lists their reliability indicators.