In this paper, test method was used to study the distribution of cutting force while blade machined with 4-axis and 5-axis NC program. The main difference between the two program was given. The difference of machining forms between 4-axis and 5-axis has led to their cutting forces distribution were different. The change of cutting force in 4-axis machining was large while the 5-axis machining was relatively stable. 5-axis cutting force had no impact comparing with 4-axis, which is more suitable for blade machining.