On 12 December 2019,a novel coronavirus disease,named COVID-19,began to spread around the world from Wuhan,China.It is useful and urgent to consider the future trend of this outbreak.We establish the 4+1 penta-group model to predict the development of the COVID-19 outbreak.In this model,we use the collected data to calibrate the parameters,and let the recovery rate and mortality change according to the actual situation.Furthermore,we propose the BAT model,which is composed of three parts:simulation of the ret rush (Back),analytic hierarchy process (AHP) method,and technique for order preference by similarity to an ideal solution (TOPSIS) method,to figure out the best ret date for university students.We also discuss the impacts of some factors that may occur in the future,such as secondary infection,emergence of effective drugs,and population flow from Korea to China.