The cumulative number of local confirmed cases was highly correlated with the total inflow population from Wuhan before the city closure, and the proportion of third-generation infections in a local region is tiny. Accordingly, we proposed an approximate method to quantitatively evaluate the regional control efficacy of COVID that takes into account effects of both imported cases and regional population. We applied this method to evaluate the control efficacy of the top-50 cities with maximum inflow population from Wuhan. The 10 cities with the most significant control efficacy are Shijiazhuang, Luoyang, Enshi, Zhoukou, Xiamen, Guiyang, Xianning, Anqing, Xinyang, and Nanning.