By　the　end　of　February　2021,　COVID-19　had　spread　to　over　230　countries,　with　more　than　100　million　confirmed　cases　and　2.5　million　deaths.　To　control　infection　spread　with　the　least　disruption　to　economic　and　societal　activities,　it　is　crucial　to　implement　the　various　interventions　effectively.　In　this　study,　we　developed　an　agentbased　SEIR　model,　using　real　demographic　and　geographic　data　from　Hong　Kong,　to　analyse　the　efficiency　of　various　intervention　strategies　in　preventing　infection　by　the　SARS-CoV-2　virus.　Close　contact　route　including　short-range　airborne　is　considered　as　the　main　transmission　routes　for　COVID-19　spread.　Contact　tracing　is　not　that　useful　if　all　other　interventions　have　been　fully　deployed.　The　number　of　infected　individuals　could　be　halved　if　people　reduced　their　close　contact　rate　by　25%.　For　reducing　transmission,　students　should　be　prioritized　for　vaccination　rather　than　retired　older　people　and　preschool　aged　children.　Home　isolation,　and　taking　the　nucleic　acid　test　(NAT)　as　soon　as　possible　after　symptom　onset,　are　much　more　effective　interventions　than　wearing　masks　in　public　places.　Temperature　screening　in　public　places　only　disrupted　the　infection　spread　by　a　small　amount　when　other　interventions　have　been　fully　implemented.　Our　results　may　be　useful　for　other　highly　populated　cities,　when　choosing　their　intervention　strategies　to　prevent　outbreaks　of　COVID-19　and　similar　diseases.