Construction project cost control generally four stages to complete, including decision-making stage and early stage work in the construction project cost control plays a vital role. Construction project cost control is the construction of a core part of project management, implemented in the whole process of construction must be in the investment decision-making stage, the preliminary work phase, implementation phase, and delivery stages of completion to take effective measures, respectively. Stage in the decision-making training to strengthen the management measures, in the early stages of work on human, material, machine cost control, computer applications in the construction phase will be to control these costs, delivery and settlement stages of completion in time to make up for shortcomings eliminate unnecessary costs later. This article describes the cost control and its main contents, lists the main methods of cost control and conditions of use, and then introduces the construction project cost control, and finally with practical examples, Yiu Wah House, Garden Expo project cost control techniques are studied, targeted project cost projections, to ensure quality in construction projects while the total costs to a minimum, in order to achieve optimum business benefits and social benefits.