In order to solve the reliability problems arising from amphibious armored vehicles in land and water conversion, proposes a method of a high reliability land and water conversion manipulation. Applying the theory and method of reliability engineering, based on fault and problem, analyzes the fault mechanism, acquires the reliability key part list of product, finds out the key factor which influences the manipulate reliability, realizes improvement of reliability technology research and forms the reliability improvement plan. Reliability modeling, allocation and prediction for reliability growth plan are carried out. The results show that the method can decrease requirements of repairing human resource and maintenance, reduce maintenance cost and guide the development and production of the products.