The whole process consulting mode can help the scientific and efficient investment decision-making and the standardized and accurate project management. Considering the influencing factors of the whole process consulting mode, the article constructs the causal loop diagram and stock flow diagram with the help of system dynamics method to clarify the role of influencing factors and the feedback mechanism, and then simulates the development trend of the whole process consulting mode after quantifying the relevant parameters, and simulates the dynamic change of the scale of the whole process consulting mode after the adjustment of the feedback parameters. Finally, the optimal path is chosen to promote the development of the whole process consulting mode in government investment projects by increasing the policy guidance and accelerating the construction of industry standards and norms, which will contribute to the healthy development of the whole process engineering consulting industry in the future.