The cumulative effect of geometric parameter errors of a single lens has a particularly prominent impact on the overall imaging quality of the optical system. Among various geometric parameters of the lens, the center thickness, wedge error and center deviation have a more significant influence on the imaging quality. Among various geometric parameters of the lens, the center thickness, wedge error, and center deviation have a significant influence on the imaging quality. To address the difficult problems in measuring geometric parameters such as thickness, center deviation, and wedge error of optical lenses and characterizing the correlation of multi-surface shapes, this article proposes a differential confocal optical lens geometric multi-parameter comprehensive measurement method based on reference ring-assisted positioning. This method uses the characteristics of the precise correspondence between the zero point of the laser differential confocal measurement curve and the focus of the sensor to achieve high-precision fixed-focus measurement of a single surface of the optical lens. Through the common reference ring-assisted positioning method, the precise positioning of the optical lens during the flip measurement of the double-sided surface is achieved. Through the reference ring attitude alignment method, the position correlation alignment and surface reconstruction of the double-sided surface of the optical lens are achieved. Finally, the comprehensive measurement and evaluation of the optical lens geometric multi-parameters are achieved. By conducting comprehensive measurements of multiple geometric parameters of the lens, the overall system can be optimized in a targeted manner, reducing repetitive positioning errors and cumulative errors. This helps improve the system′s accuracy, enhances imaging quality, and ultimately boosts the overall comprehensive performance of the optical system. Experimental verification shows that the measurement error of the optical lens thickness is less than 1.200 μm, the measurement error of the center deviation is better than 1.000 μm, and the wedge error is less than 0.002°. This method provides a new technical approach for the measurement of optical lens geometric multi-parameters.