The invention discloses a railway engineering construction plan optimization method, which comprises the following steps: basic data of railway engineering construction activities is acquired; the constants and variables are determined according to the basic data, and the optimization model of railway engineering construction plan with constraint conditions and objective function is established; the objective function is an objective function with the lowest cost in the case of constraining the expected construction period of the project or an objective function with the shortest constructionperiod in the case of constraining the expected cost of the project; according to the basic data, the optimization model of railway engineering construction plan is solved, and the optimal scheme of railway engineering construction plan is obtained; the construction plan diagram according to the optimal scheme of the railway construction plan is drawn. The invention can realize the optimization ofthe construction plan of the railway construction project under the condition of the existence of the bi-directional construction activity and/or the existence of the non-typical construction activity, and obtain the global optimal construction plan. The invention can realize the optimization of the construction plan of the railway construction project under the condition of the existence of thebi-directional construction activity and/or the non-typical construction activity.