Aiming　at　the　task　offloading　in　edge　computing,　this　paper　proposes　a　task　offloading　algorithm　that　utilizes　the　cache　function　of　the　edge　server.　When　a　task　is　uploaded　to　the　edge　server,　it　is　determined　whether　this　type　of　task　is　uploaded　to　the　edge　server　for　the　first　time.　If　it　is　determined　to　be　yes,　then　the　corresponding　task　content　is　cached　on　this　server,　and　each　task　is　set　to　have　been　cached　the　same.　The　execution　delay　and　energy　consumption　of　computing　nodes　of　type　content　will　be　reduced.　When　a　task　that　has　cached　the　same　type　of　content　is　uploaded　to　the　edge　server,　the　pre-set　evaluation　parameters　take　into　account　factors　such　as　delay　and　energy　consumption　to　calculate　the　optimal　processing　position　for　the　task,　so　that　each　uploaded　task　can　be　executed　in　the　least　costly　manner,　thereby　achieving　the　purpose　of　reducing　the　operating　cost　of　the　entire　system.　We　use　iFogSim　simulator　for　simulation　experiments.　Simulation　results　show　that　this　strategy　can　effectively　reduce　the　latency　and　energy　consumption　of　edge　systems.　In　the　ideal　case,　the　task　latency　and　energy　consumption　are　reduced　by　15%　and　18%　respectively　compared　to　the　original　algorithm.　©　2020　ACM.