Most energy resources used in Taiwan are imported, and Taiwan has been encountering the power shortage problem in recent years. The railway operator is a heavy user of the power system, and energy saving is an important topic for the railway operation. Therefore, an object-oriented programming (OOP) simulation system is developed to assess the energy saving efficiency of train operation. The simulation system was built by Visual C++ on the basis of object modeling technique (OMT). Three models of OMT are utilized, and they are object model, dynamic model, and function model. The simulation system consists of a train movement simulator, a train dispatching simulator, and a power consumption simulator. We test the following energy saving strategies: (1) maximum speed reduction, (2) reduced acceleration rate, (3) anticipatory coasting, and (4) saw-tooth coasting. The major findings in the case study of Taiwan’s high-speed railway are as follows. (1) The relationship of running time and power consumption is not linear, (2) the reduction of maximum speed is effective for all-stop train service, (3) the anticipatory coasting is effective for three-stop or direct train service, and (4) the anticipatory coasting is also effective for a test of timetable operation.