In 2020，the net financing of the credit bond market rose rapidly，while at the same time the amount of defaulted bonds hit a record high，and the structure of defaulted companies was dominated by state-owned enterprises. A total of five SOEs have defaulted since the second half of 2020，of which Yongcheng Coal and Electricity，as an over-expected high credit-grade default and asset transfer before default，showed an obvious low willingness to repay debts，shaking the foundation of credit bond analysis and bringing adverse impact to the market，leading to a significant increase in the number of delayed or cancelled issuance of credit bonds in November and a continuous upward trend in credit spreads. Meanwhile，a coal SOE in Henan Province，its default resulted in no new issuance of Henan bonds for 46 consecutive days，and the coal industry also continued to have negative net financing for 11 consecutive weeks. Compared with foreign rating agencies，we believe that the current credit bond rating in China is low in differentiation and has a weak default predictive power，while the implied rating of Chinese bonds may be a better approach.