In order to improve the design of reciprocating pump, two design methods on fatigue reliability, which are based on the most hazardous cross-section and finite element analysis respectively, were put forward. A practical object-oriented application software about fatigue reliability analysis on pump crankshaft was developed by several senior programming technologies via VC++ 6.0. By this software, the fatigue reliability analysis can be fulfilled by two approaches and six methods. Calculating example and practical applications indicated that this software have a lot of merits such as friendly interfaces, simply and reliable operation, high precision and good application prospect.