Abstract: To address industry challenges such as low machining accuracy and poor process stability in ram-type components caused by large-span coaxial hole structures. A dedicated dual-sided CNC horizontal boring and milling machine is developed in this research. Through innovative machine structure and measurement compensation systems, machining quality and efficiency of rams are significantly improved. The machine is characterized by a dual-host opposed layout, with two sets of columns mounted on the same longitudinal bed. This configuration ensures Z-axis coaxiality of the spindles. The coaxiality bottleneck in processing ram spindle bores on gantry-type boring and milling machines is effectively resolved by this design, the quality of ram components is improved, and heat generation during high-speed spindle rotation is reduced.Verification confirms that coaxiality of rams machined by this equipment achieves 0.02 mm, meeting project requirements.