China has abundant heavy⁃oil resources, but their exploitation is challenging and field recovery is relatively low; therefore, improving recovery efficiency is important for ensuring stable petroleum production. Thermal recovery is widely used in heavy⁃oil production, and steam quality is a key parameter affecting thermal recovery performance. However, real⁃time in⁃situ direct measurement remains difficult. At present, domestic field measurements mainly rely on manual chemical titration, which has a significant time lag and cannot meet online real⁃time monitoring requirements. In this study, a new method for measuring wet saturated steam quality based on the matrix conductance principle is proposed. Under operating conditions of 17 MPa and 310 °C, a primary sensing element was designed for a steam⁃injection pipe with an inner diameter of 64 mm and an outer diameter of 89 mm. Material selection, system sealing, and fixture design were completed to ensure stable data acquisition and accurate measurement. An algorithmic model for the matrix conductance method was then established, and the parameters affecting steam quality were analyzed. The weighted discretization method and the conventional discretization method were compared through calculation and error analysis. The results show that the maximum relative error of the conventional discretization method reaches 11.5%, whereas weighted discretization method, with a maximum relative error of only 3.9%.The weighted discretization method therefore provides higher measurement accuracy than the conventional discretization method.