The　public＇s　risk　perception　of　public　health　emergencies　will　determine　their　behavior　choices　to　a　certain　extent.　Research　on　public　risk　perception　of　emergencies　is　an　integral　part　of　crisis　management.　From　the　perspective　of　the　whole　life　cycle,　this　article　takes　the　COVID-19　epidemic　as　an　example.　It　conducts　empirical　analysis　to　study　the　influencing　factors　of　public　risk　perception　of　public　health　emergencies.　The　results　show　that:　(1)　the　public＇s　risk　perception　is　affected　by　individual　factors,　event　characteristics,　social　influencing　factors,　and　individual　relationship　factors.　(2)　The　more　the　public　is　familiar　with　the　epidemic,　the　lower　the　risk　of　the　epidemic.　The　more　the　public　can　control　the　loss　of　the　epidemic　risk,　the　perceived　epidemic　risk　will　be　reduced.　The　more　the　public　trusts　the　supreme　power　of　the　government,　the　lower　the　risk　of　the　epidemic　in　their　hearts　is.　The　higher　the　closeness　of　the　risk　and　impact　of　the　epidemic　to　individuals,　the　higher　the　level　of　risk　perception　is.　(3)The　public＇s　risk　perception　will　evolve　with　the　development　of　the　situation,　and　there　are　differences　in　recognition　of　government　departments＇　control　measures　at　different　stages　of　public　health　emergencies.　The　relevant　departments　should　effectively　guide　the　public＇s　risk　response　behavior　in　combination　with　the　life　cycle　of　public　health　emergencies.　The　research　conclusions　of　this　article　clarify　the　dynamic　evolution　of　risk　perception　and　provide　a　specific　reference　for　the　emergency　management　of　public　health　emergencies.