Inhibiting the shuttle effect, accelerating sulfur redox kinetics and controlling lithium homogeneous deposition are significant to achieve the flexible lithium-sulfur (Li-S) cells with high energy density and safety. In this study, we successfully synthesized a three-dimensional (3D) free-standing necklace-like fabric consisting of heterostructured Ni/Ni4N nanoparticles confined into hollow carbon cages implanted with N-doped carbon nanofibers (Ni/Ni4N@NCC). This unique 3D necklace-like framework and interface electronic structure of Ni/Ni4N@NCC could effectively addresses the challenges associated with both sulfur cathode and lithium anode in Li-S cells. Combine with experimental tests and DFT simulations, Ni/Ni4N@NCC not only strengthened chemical anchoring and accelerated lithium polysulfides conversion, but also induced Li uniform deposition and growth due to its excellent lithiophilicity and low Li diffusion energy barrier. For the anode, the lithium foil coating with Ni/Ni4N@NCC interlayer (denoted as Li-Ni/Ni4N@NCC anode) showed exceptional long-term cycling stability over 1000 h at the high current density of 5 mA cm−2 for high areal capacity of 5 mAh cm−2. The S-Ni/Ni4N@NCC||Li-Ni/Ni4N@NCC cell with sulfur loading (6.8mg cm−2) exhibited high areal capacities of 6.11 mAh cm−2. The synergetic effect of fascinating necklace-like structure and heterogeneous interface offer instruction for the practically viable design of high-performance flexible Li-S full cells.