The outbreak and global spread of coronavirus have become major public health events that countries around the world need to face together. At the same time of the spread of virus，the spread of various rumors on the internet has spread rapidly like epidemics，causing “infodemic”. This paper takes “COVID-19” related rumors as research samples to construct a new rumor propagation model：R（rumor）=I（importance）×A（ambiguity）×E（emotion）/L（media literacy）. The rationality of rumor propagation model was verified by empirical research. At last，the paper puts forward the countermeasures of network rumor information governance and provides some references for future research.