In order to solve the problem of time cost estimation in the development of geographically distributed software projects, the factors that influence development time and efficiency of geographically distributed development has be studied, and the actual situation of distributed software development is considered synthetically. The cost driving factors of COCOMOⅡ model are analyzed, screened, and newly increased. The COCOMOⅡ model is improved on this basis, so that the improved COCOMOⅡ model can reasonably estimate the time and cost of the distributed software development project. Finally, the development time and cost estimation of the improved COCOMOⅡ model are realized. The improved COCOMOⅡ model can better estimate the workload and the development progress of the distributed development.