To　improve　the　fuel　consumption　and　emission　performance　of　a　plug-in　hybrid　electric　vehicle　(PHEV),　this　paper　builds　a　multi-objective　control　strategy　using　equivalent　consumption　minimization　strategy　which　the　core　is　determining　the　equivalence　factor.　Firstly,　based　on　the　established　PHEV　model　and　cost　function　of　multi-objective　optimization,　an　equivalent　factor　optimization　model　combining　the　fuzzy　proportional　integral　controller　is　constructed.　Then,　particle　swarm　optimization　(PSO)　algorithm　is　adopted　to　get　more　accurate　proportion　and　integral　coefficient　by　optimizing　membership　function　and　control　rules　and　then　obtains　more　accurate　equivalent　factor　to　distribute　the　power　between　different　power　components　reasonably.　Therefore,　the　PSO-fuzzy　based　multi-objective　optimization　control　strategy　for　PHEV　with　equivalent　factor　adaption　is　designed.　Finally,　simulation　analysis　and　research　on　the　proposed　control　strategy　are　carried　out　based　on　the　actual　driving　cycle　of　Fuzhou　city.　Results　show　that　the　proposed　control　strategy　can　improve　the　fuel　economy　and　emission　performance　of　the　PHEV　significantly.　Compared　with　the　general　fuzzy　control　strategy,　the　PSO-fuzzy　based　control　strategy　can　reduce　the　equivalent　fuel　consumption　by　9.0%,　HC　emissions　by　2.7%,　CO　emissions　by　2.9%　and　NOx　emissions　by　7.8%,　respectively.　©　2021,　Editorial　Department　of　Control　Theory　&　Applications　South　China　University　of　Technology.　All　right　reserved.