In today's society, investment decision-making has become one of the main decisions of every large-scale company. The management and shareholders of the company conduct reasonable analysis and vote for high-quality investment plans. The paper mainly shows the impact of economic models on project decision-making, and mainly summarizes the relationship between the economic model NPV and IRR and its application loopholes in actual situations. The final results of the paper show that the economic models NPV and IRR have their own advantages and disadvantages, and they need to be used reasonably according to the situation. Second, investors do not have to follow economic models to make decisions. When faced with investment decisions, they should adapt to the current situation.