Objective In the process of infectious disease transmission it tends to go through repeated infections with multiple transmission peaks. Based on this characteristic a multi - band Richards model was proposed to numerically simulate the number of infected people of infectious diseases. Methods The multi-band Richards model was used in conjunction with the least squares method to fit the cumulative infection cases in the Western Pacific region. Estimated values of parameters including infection rate inflection point and final number of infections were obtained and convergence was evaluated to determine the number of bands and the inflection dates for each band in the spread of the disease. Results The results showed that the infectious disease outbreak in the Western Pacific region from January 4th 2020 to September 13th 2020 was divided into 3 bands with the inflection points on March 15th and July 4th separating the three bands. The basic reproduction number obtained from the first band was about 8. 53 indicating a strong transmission capacity of the disease. Conclusion With the help of the multi-band Richards model the infection of multi- band infectious diseases can be effectively fitted and the key turning points of infectious diseases in multistage outbreaks can be identified as well as the scale of infections in the coming period can be predicted which can provide a reference for the development of preventive and control measures for infectious diseases.