This paper introduces anticipated news shocks, unanticipated surprise shocks and noise shocks into the incomplete information structure of Chinese quantitative monetary policy. By estimating an incomplete information SVAR and a NK-DSGE model with financial frictions, we find that (1) News shocks, surprise shocks and noise shocks of expansionary monetary policy increase output with a descending order on impact scale. Introducing information friction improves the model’s fitting effect on reality. (2) Noise shocks “pollute” news shocks’ effects by slowing down and eliminating cumulative impacts of monetary policy. (3) Financial frictions exaggerate fluctuations in business cycles caused by information frictions and monetary policy targeting leverage increases welfare. The results indicate that PBC should eliminate noise in policy signals and improve policy transparency by communicating with the public more frequently and effectively.