Abstract: With the rapid development of 5G technology, millimeter-wave communication has become a critical research direction due to its high-efficiency transmission characteristics. However, the significant insertion loss of millimeter-wave signals penetrating glass limits their indoor communication applications. Therefore, enhancing millimeter-wave transmission capability through transparent media has emerged as a key research focus. Based on the generalized Snell's law and wide-angle frequency selective surface theory, this paper proposes an optically transparent metasurface operating at 27.2 GHz. The design achieves signal focusing to enhance field strength in primary communication zones while incorporating a wide-angle incident metasurface to improve transmission efficiency for obliquely incident electromagnetic waves. Experimental results demonstrate that the focal field strength at 0-40° incidence angles increases by approximately 5.3 dB, 4.1 dB, 5.3 dB, 8.3 dB, and 7.4 dB compared to bare glass, with the central field strength being 16 dB higher than the edge. Simulations and measurements show that the proposed wide-angle metalens improves S21 by 3.5 dB (0° incidence) and 4.6 dB (40° incidence) over bare glass. By analyzing transmission enhancement techniques from both incident and exit perspectives, this work significantly improves transmission efficiency in the 5G millimeter-wave band, providing novel insights and technical support for advancing 5G millimeter-wave communication systems.