<p>Laser powder bed fusion (LPBF) offers a viable solution to the challenges of deformation, instability, and vibration commonly encountered during the conventional machining of thin-walled structures. Appropriate scanning strategies can further improve the forming quality of such structures produced via LPBF. However, due to the influence of structural size effects and the thermal conductivity of materials, the impact of scanning strategies on the LPBF process performance for titanium alloy thin-walled structures remains insufficiently understood. Herein, a combined approach involving experimental processing and thermal simulation was employed to investigate the effects of scan line sizes and wall thickness on the forming quality of titanium alloy thin-walled specimens. The results indicated that zigzag scanning yielded superior surface roughness and lower porosity compared to island scanning. As wall and scan line sizes decreased, the adverse influence of the groove-like morphology induced by island scanning became more pronounced, leading to reduced dimensional accuracy and degraded surface quality. Although significant residual stresses were observed across all scanning strategies, zigzag scanning exhibited higher interlayer peak temperatures, which contributed to improved surface integrity. In contrast, island scanning resulted in lower interlayer peak temperatures, further exacerbated by the groove-like morphology, thereby deteriorating surface quality. These findings provide valuable guidance for the selection of optimal scanning strategies in the LPBF fabrication of titanium alloy thin-walled components.</p>