Abstract: Under the background of slowing down of urbanization and increasing household debt ratio, China's real estate industry is facing many challenges. Excellent cost control methods can effectively solve the problems of weak cost control ability and low cost budget accuracy, help real estate developers to win the competition in the limited market share, and achieve long-term development. This paper puts forward the improved target operation cost method based on big data technology to the cost control of the real estate construction process, and focuses on the role of big data technology on cost control. Finally, the suggestions and methods of cost control are put forward from four aspects: standardizing the target operation cost management process, strengthening the personnel theory training, improving the performance appraisal system, and optimizing the cost control system, and it’s wished to provide a useful reference for the cost control of real estate developers.