Symmetry is a universal structural property of networks and many real networks have this characteristic. Presently,
reducing an original network to a small-size quotient network by means of network symmetry is a promising
method for network reduction. This paper studies the synchronization relationship between an original network and its
quotient network and concludes that the network and its quotient network reach frequency synchronization simultaneously.
We analyze the conclusion in theory and validate it with several simulations on synthetic networks.