As　of　May　2024,　the　main　strains　of　COVID-19　caused　hundreds　of　millions　of　infection　cases　and　millions　of　deaths　worldwide.　In　this　study,　we　consider　the　COVID-19　epidemics　with　the　main　strains　in　the　Chinese　mainland.　We　study　complex　interactions　among　hosts,　non-pharmaceutical　interventions,　and　vaccinations　for　the　main　strains　by　a　differential　equation　model　called　SVEIR.　The　disease　transmission　model　incorporates　two　strains　and　protection　awareness　of　the　susceptible　population.　Results　of　this　study　show　that　the　protection　awareness　plays　a　crucial　role　against　infection　of　the　population,　and　that　the　vaccines　are　effective　against　the　circulation　of　the　earlier　strains,　but　ineffective　for　emerging　strains.　By　using　the　next　generation　matrix　method,　the　basic　reproduction　number　of　the　SVEIR　model　is　firstly　obtained.　Our　analysis　by　Hurwitz　criterion　and　LaSalle＇s　invariance　principle　shows　that　the　disease　free-equilibrium　point　is　locally　and　globally　asymptotically　stable　when　the　threshold　value　is　below　one.　The　existences　of　endemic　equilibrium　points　are　also　established,　and　the　global　asymptotic　stabilities　are　analyzed　using　the　Lyapunov　function　method.　Further,　the　SVEIR　model　is　confirmed　to　satisfy　the　principle　of　competitive　exclusion,　of　which　the　strain　with　the　larger　value　of　the　basic　reproduction　number　is　dominant.　Numerically,　the　surveillance　data　with　the　Omicron　strain　and　the　XBB　strain　are　split　by　the　cubic　spline　interpolation　method.　The　fitting　curves　against　the　surveillance　data　are　plotted　using　the　least-squares　method　from　MATLAB.　The　results　indicate　that　the　XBB　strain　dominates　in　this　study.　Moreover,　a　global　sensitivity　analysis　of　the　key　parameters　is　performed　by　using　of　PRCC.　The　numerical　simulations　imply　that　combination　control　strategy　positively　impacts　on　the　infection　scale　than　what　separate　control　strategy　does,　and　that　the　earlier　time　producing　protection　awareness　for　the　public　creates　less　infection　scale,　further　that　the　increment　of　protection　awareness　also　reduces　the　infection　scale.　Therefore,　the　policymakers　of　the　local　government　are　suggested　to　concern　the　changes　of　protection　awareness　of　the　public.　©　2024　The　Authors