Abstract: The purpose of this paper is to reveal the spread dynamics of COVID-19, SARS and MERS. Based on the growth rate and infection inhibition constant of infectious diseases, the propagation growth model of infectious diseases is established, and then the parameters of the propagation growth model of three coronavirus, SARS-CoV-2, SARS-CoV and MERS-CoV, are obtained by nonlinear fitting. The analysis shows that the growth rate of SARS-CoV-2 is about twice that of SARS-CoV and MERS-CoV, and the doubling period of SARS-CoV-2 is two to three days. The infection inhibition constant in Hubei province is two orders of magnitude lower than that in other areas, which is consistent with the situation in Hubei.