Abstract: Laser cladding and milling remanufacturing of TC4 alloy thin-walled parts was carried out, and the influence of cladding trajectory (0°, 45° and 90°) and subsequent milling on the flatness of thin-walled parts was studied by using MATLAB software to fit the test data. The results show that after laser cladding with 0°, 45° and 90° cladding trajectories, the flatness of TC4 alloy thin-walled parts was improved comparing with that before cladding, and the flatness difference before and after cladding increased sequentially. The hardness of the TC4 alloy laser cladding layer was 20% higher than that of the matrix. After milling, the flatness of the thin-walled parts after laser cladding was further increased. The flatness of thin-walled parts with 90°, 45°, and 0° cladding trajectories decreased after milling, and the 0° cladding trajectory showed a better remanufacturing effect on titanium alloy thin-walled parts.