Abstract: In Fused Deposition Modeling (FDM) technology, the warping of printed parts is one of the key factors restricting the improvement of printing accuracy. A thermo-mechanical sequential coupled finite element method is used to investigate the warping deformation behavior and geometric compensation of polylactic acid (PLA) during the FDM process. First, the impact of time step size on the simulation results is systematically analyzed. Then, the role of raster angle in controlling distortion is explored. Finally, a method involving inverse geometric model compensation is implemented to effectively compensate the distortions in the fabricated parts. The results show that: the time step size has a significant effect on the temperature field distribution, but has little direct impact on the deformation results. This is due to the high sensitivity of temperature changes to time, while the deformation depends more on cumulative effects and quasi-steady-state balance. Additionally, it is found that adopting a 0°/90° alternating strategy can reduce the stress concentration. Compared to the single 0° or 45° angle, the maximum stress is reduced by 12.7%, effectively alleviating the warping problem. After implementing the reverse compensation strategy, the manufacturing accuracy is significantly improved by 62.07%. Consequently, reasonable selection of raster angle combined with reverse compensation design strategies can effectively restrain the warping problem in the FDM process, enhancing manufacturing accuracy and product quality.