With the continuous improvement of IT technology, informatization and digitization have become the important driving en- gines for the management improvement and business promotion of most medium and large enterprises, and the demand for informa- tion system software of various types of enterprises is also increasing. However, in terms of software cost evaluation, it is difficult for Party A and Party B to reach an agreement on the project scale, workload and R & D cost, so the unified evaluation standard and basis are urgently needed. This paper introduces the function point method, and explains the application of NESMA function point method in software cost in detail, which provides a standard for the unified understanding of project Party A and Party B, and pro- vides the basis for enterprises to standardize the cost evaluation system.