This paper mainly discusses 2 dynamic routing protocols—centralized routing protocol and distributed routing protocol. By comparing and contrasting the two routing protocols, the author expatiates on the principles of both routing protocols, including how they work, how they affect the network performance, and the advantages and disadvantages of these two protocols. In addition, the author gives 2 examples of basic algorithms —Distance Vector Algorithms and Link State Algorithms, which are used by Distributed Routing Protocol. In the end, the result suggests that in order to achieve routing optimization based on specific network environments, the mixed routing protocol which combines centralized routing protocol with distributed routing protocol should be commendatory.