Abstract: Objective: The purpose of the study is to provide theoretical basis and reference for the selection of high\|speed railway project construction timing, to improve the reliability of investment decision\|making and reduce investment risks. Method: The real options in the verification process of timing selection for high\|speed railway project construction are introduced. By identifying the types of options involved in investment decision\|making for high\|speed railway projects, with a focus on the option of deferral, a modeling and analysis is conducted on major uncertainties such as construction costs, passenger flows, and passenger time saving values involved in the investment process. The Monte Carlo simulation is realized with the OptQuest optimization tool in the Crystal Ball software, to determine the optimal timing for high\|speed railway project construction under the condition of maximizing net present value. An empirical analysis is conducted using the example of the high\|speed railway project A in western China. Result &Conclusion: The high\|speed rail project features great construction difficulty, long construction period, and huge investment, with significant uncertainty in cost and return increase over time. The method of analyzing the construction timing of the high\|speed rail project based on real options provides a framework for assessing and estimating such uncertainty. According to this analysis method, delaying the construction of project A by 18 years will reach the optimal net present value.