Construction cost control plays a key role in the process of construction cost control during the construction phase, which determines the economic benefits of construction enterprise. This thesis tries to analyze the price deviation during the construction phase based on the cost control principles in the construction phase. At the same time, it will combine with the PDCA circulation theory so as to establish its model by combining with the Earned Value Management. For the deviation of the price, we can control it through the organization, technology, economy and contract measures. Through the empirical analysis, this cycle can analyze the cost deviation accurately during the construction phase of engineering project, and then provide the correspondent control measures to correct deviation. Therefore we can eventually realize the cost control target of construction enterprise. The research shows that it is practical to introduce the PDCA cycle to the construction cost control, and the cost is controlled progressively.