Abstract: To address key challenges in hybrid additive-subtractive manufacturing of heterogeneous materials, such as insufficient forming accuracy and complex coupling relationships between additive and subtractive processes, this study systematically investigates the process characteristics of heterogeneous material hybrid manufacturing. The response surface methodology is adopted to build prediction models, in order to correlate welding current, wire feed speed, and travel speed with surface roughness and layer overlapping quality. Optimal process parameters for dual-wire additive manufacturing of high-strength steel and stainless steel are determined, significantly improving the surface quality of deposited layers. The milling process for additive manufactured heterogeneous components is also investigated, with key parameters including spindle speed, feed rate, and cutting depth optimized to enhance machining quality. Furthermore, the influence of subtractive process on additive manufacturing quality is analyzed, and a rational alternating strategy for additive and subtractive steps is proposed. The proposed scheme effectively mitigates weld bead collapse caused by heat accumulation and markedly improves forming stability. The research provides a foundation for process optimization and quality control in hybrid additive-subtractive manufacturing of heterogeneous materials, offering significant value for advancing the application of this technology in large-scale complex component fabrication.