As a pillar industry of the national economy, the construction industry plays an important role in promoting economic growth, social stability and improvement of quality of life of people. Influenced by the deepening reform of the market economy system and the normal prevention and control of the COVID-19 epidemic, the construction market has increasingly high requirements and the market competition is becoming increasingly fierce. The major enterprises compete with each other to obtain the project at a low price, which seriously disturbs the market order and further compresses the market profit space. In the limited market share, in order to improve their competitiveness, cost control has become the focus of construction enterprises. This paper analyzes the current situation of cost control of construction projects in construction enterprises, finds out the existing problems and puts forward countermeasures and suggestions in order to realize the dynamic cost control of the whole process of construction projects.