2D　Janus　transition　metal　dichalcogenide　(TMD)　semiconductor　materials　have　attracted　great　interest　for　their　potential　applications.　Because　of　the　increased　requirement　for　thermal　management　in　2D　devices　with　single-atom　thickness,　a　fundamental　understanding　of　interfacial　thermal　conduction　(ITC)　has　emerging　significance.　In　this　work,　the　ITC　of　in-plane　heterostructures　constructed　using　MoSSe　and　WSSe　is　reported.　In　addition　to　the　interface　connected　normally　by　MoSSe　and　WSSe　with　the　same　type　of　chalcogen　atoms　are　on　the　same　side　of　left　and　right　sections,　inversional　interface　by　rotation　of　180　degrees　of　WSSe　is　also　considered,　in　which　S　atoms　are　on　the　opposite　side　of　the　left　and　right　sections.　Interestingly,　the　ITC　in　the　normally　connected　heterostructure　is　found　to　be　almost　twice　as　much　as　that　in　the　inversely　connected　heterostructure.　The　unusually　large　change　in　ITC　is　attributed　to　the　bending　curvature　and　additional　discontinuity　in　the　inversely　connected　heterostructure.　Euler-Bernoulli　beam　model　gives　further　insight　into　the　origin　of　such　interface　bending.　The　findings　offer　the　very　first　insight　into　the　phonon　transport　in　Janus　heterostructures,　and　benefit　thermal　management　of　2D　devices　based　on　Janus　monolayers.