Epidemiology reveals mask wearing by the public is crucial for COVID-19 control

•Epidemiology reveals mask wearing by the public is crucial for COVID-19 control•COVID-19 is mainly transmitted by saliva droplet which containing considerable copies of virus. Asymptomatic carriers are the main source of infection.•Under different public health policies, infection curve responded more sensitively than daily reported cases and reveals that wearing mask by the public is the most efficient way to reduce daily infection cases.•Our results elucidated the importance of daily infection curve in the assessment of efficiencies of prevention measures in an epidemic outbreak.•Mask wearing by the public will be an important policy during the lifting of lockdown, as continued wearing masks can help prevent the epidemic from spreading again.