In order to enhance the core capacity of optical fiber composite overhead ground wire（OPGW）, a 180 μm fine diameter single-mode optical fiber was developed. Research was conducted from two aspects: fiber profile structure design and optimized coating technology. The attenuation, stress-strain, and environmental performance of the 180 μm fine diameter OPGW optical cable were verified. The experimental results show that the attenuation of the entire 180 μm fine diameter fiber is stable during the cabling process. The tensile stress-strain performance and environmental performance of optical cables meet and exceedthe power industry standard requirements of OPGW cables, and have stable reliability and practical application feasibility.