Supercapacitors have advantages such as high power density, extended lifetime, and fast charging rate, which make them good energy-storage devices. Laser-induced graphene (LIG) is a widely used electrode material for double-layer electric capacitors; however, double-layer LIG electric capacitors typically exhibit low electrochemical performance, and the addition of active materials improves the supercapacitor performance. To control the incorporation of active substances, we propose a method for preparing LIG-Fe₃O₄ composite-based micro-supercapacitor by laser direct writing polyimide (PI) films coated with Fe(NO₃)₃. The laser treated area will simultaneously undergo PI film ablation and Fe (NO₃)₃ decomposition, resulting in LIG-Fe₃O₄ composite electrode composed of Fe₃O₄ and LIG.The performance of the prepared LIG-Fe₃O₄ composite-based micro-supercapacitor has been improved by 7.58 times compared to LIG-based micro-supercapacitor. The proposed method establishes a new route for preparing high-performance LIG-based micro-supercapacitor.