Angular momentum is an important concept in mechanics. In this paper, the concepts of orbit angular momentum and rotation momentum of a system of mass points are established in classical mechanics to make the theory more complete. The application significance is illustrated by several examples. Introducing orbit angular momentum and rotation momentum into classical mechanics can help students deepen their understanding of angular momentum, establish a relationship with orbit and spin angular momentum in quantum mechanics, and deeply understand the similarities and differences between spin angular momentum in classical and quantum mechanics.