The practical application of lithium (Li) metal for next-generation rechargeable batteries is still hampered by uncontrolled growth of Li dendrite and severe volume change under repeated plating/stripping. Introducing a 3D structure to reserve space for Li storage and inducing uniform plating/stripping by a lithophilic interface layer are effective strategies to solve these problems. Herein, a novel 3D composite Li anode (Fe-N@SSM-Li) is constructed via an in situ reaction between Li and lithiophilic Fe2N/Fe3N (Fe-N) uniformly anchored on a stainless-steel mesh (SSM). The unique lithiophilic-conductive structure of the Fe-N@SSM-Li can stabilize the Li anode by effectively inducing uniform and dense deposition and confining Li deposition inside the Fe-N@SSM-Li to alleviate volume changes. The Fe-N@SSM-Li displays a distinguished electrochemical performance, with superior lifespan of 5000, 2250, and 1350 h under 1 mA cm−2/1 mAh cm−2, 5 mA cm−2/3 mAh cm−2, and 20 mA cm−2/3 mAh cm−2 in symmetric cells, respectively. Combined with this highly stable Fe-N@SSM-Li, the full cells using LiFePO4 (LFP) and S/C cathodes both show significantly improved electrochemical performances. This work provides a low-cost and scalable strategy for the construction of high-efficiency Li anode with a novel 3D structure, offers new insights to the research of Li metal batteries and beyond.