The demand for communication base stations in the 5G era has increased dramatically, the current large-scale transmission towers are important carrier for 5G equipment sharing construction. For the transmission system, the current and previous load code for the design of overhead transmission line in China are investigated. Different wind load specification on the conductors, ground wires and 5G equipment on the transmission towers are studied in finite element coupling model. In addition, the influence of soil and electromagnetic is also considering in calculation model. According to mechanical and simulation model, the structural response of the transmission tower with sharing 5G antenna including different mounting height and arrangement is discussed. Finally, comparison on maximum stress ratio of different horizontal span and overall safety of shared tower is evaluated.