Abstract: Design and development of a geometric performance testing system for optical fiber coating layers was conducted, based on geometric parameter measurement methods for coating layer stipulated in IEC 60793-1-21: 2001 and Specification for optical fibre test methods—Part 21: Measurement methods and test procedures for dimensions—Coating geometry (GB/T 15972.21—2008). Digital image processing technology was employed to conduct in-depth analyses of the tested optical fiber images at various rotation angles. Through finite point fitting of the optical fiber end face, geometric parameters of the optical fiber were measured, including cladding, primary coating layer, and secondary coating layer. Test results were then analyzed and verified through comparison. The findings indicated that test results of the system were largely consistent with those of similar foreign measuring equipment, thereby demonstrating high accuracy.