We first estimated the epidemic trend in Wuhan, China assuming the current prevention and control measures are insufficient. In this process, S was assumed to be the population of Wuhan City (11 million)15,34. The initial assumed number of cases caused by zoonotic exposure was 40 (I) according to Imai et al.’s9 estimation. We proposed E at 20 times of I in accordance with Read et al.13. R was set as 0. σ was set as 1/5.2 according to the latest article by Li et al.15, which calculated the mean incubation period of COVID-19 to be 5.2 days. Chen et al.6 calculated the average hospitalization period of 31 discharged patients to be 12.39 ± 4.77 days. Yang et al.24 calculated the median time from disease onset to diagnosis among confirmed patients to be 5. γ was accordingly set as 1/18 (ceiling of 12.39 ± 5 is 18). R0 was chosen based on Imai et al.’s9 estimation 2.6 (1.9–3.1) assuming 4000 (1000–9700) infections as of 18 January.