The bond market in China has become more important than the stock market, and understanding the risks involved is crucial. By analyzing daily interest rate data, researchers found that different types of bonds are connected in a network where risk can spread. Bonds with high liquidity, trading volume, and credit ratings are more important. The inter-bank market plays a key role in the bond market, along with interest rate bonds, bank bonds, and urban investment bonds. Changes in interest rates affect the risk spreading in the bond market. To manage risks effectively, it is essential to have strict supervision and regulation in place, and to use indicators like structural entropy for monitoring.