The　development　of　additive　manufacturing　(AM)　technology　exhibits　potential　for　the　design　and　manufacturing　of　complex　lattice　structures.　Herein,　a　novel　design　strategy　is　proposed　for　the　lattice　unit　cell　configurations,　including　triangular　prism　(T),　quadrangular　prism　(Q)　and　hexagonal　prism　(H),　by　considering　the　tight　spatial　arrangement　and　manufacturing　constraints.　Moreover,　the　influence　of　altering　the　degree　of　freedom　of　nodes,　caused　by　additional　struts,　on　mechanical　performance　and　energy　absorption　capacity　is　systematically　investigated　by　theoretical　modeling,　experimental　characterization　and　finite　element　method.　A　series　of　lattice　core　sandwich　panels　is　designed　and　manufactured　by　selective　laser　melting　(SLM).　X-ray　micro-computed　tomography　(μ-CT)　is　carried　out　to　obtain　the　realistic　geometrical　information.　Quasi-static　uniaxial　compressive　tests　are　performed　to　investigate　the　failure　mechanism　and　mechanical　performance.　The　results　reveal　that　the　joint　connectivity　of　the　unit　cell　increased　with　the　increase　of　the　number　of　the　struts,　resulting　in　superior　compressive　modulus　and　ultimate　strength.　The　main　deformation　mode　of　cells　is　gradually　changed　from　bending-dominated　to　stretch-dominated　with　the　increase　of　the　joint　connectivity.　The　proposed　design　ensures　the　performance　consistency　of　the　manufactured　struts　and　facilitates　the　theoretical　predictions　and　analysis.　Furthermore,　the　specific　energy　absorption　of　the　structure　also　increased　with　the　increase　of　joint　connectivity.　In　the　case　of　unit　cells　with　different　configurations,　T　series　rendered　superior　specific　strength　and　specific　energy　absorption,　whereas　Q　series　exhibited　excellent　specific　stiffness.　©　2020　Elsevier　B.V.