Since the introduction of software engineering concept in 1968, it has experienced the development of nearly 50 years. The scale and complexity of software system have been increasing day by day. However, since the 1970s, there has been a delay in the progress of a large number of software projects. And quality defects for the typical characteristics of the software crisis, is still frequent. Software cost estimation in the software engineering development process has been playing an important role. The precise software cost estimate is the guarantee of software engineering on time. In this study, a similarity measure based on Pearson correlation coefficient is used, and the software cost estimation is carried out by using the TOPSIS method to estimate the cost of the project with the closest project. Finally, the method is applied to the Desharnais dataset and compared with other methods. The experimental results show that the software cost measurement method based on the correlation coefficient has better accuracy than the existing similarity measure method.