It is of great significance to study the energy dissipation characteristics of bolted joints under transverse alternating loads especially for analyzing the dynamic response of transmission tower structures and enhancing its safety and reliability. In this paper, a combination of finite element simulation and experiments is used. Firstly, the finite element model of bolted joint of transmission tower is established, and the load–displacement curve is obtained by applying transverse alternating load on the end face of angle steel. Afterwards, a fatigue test machine is used to apply cyclic load to six different joints. In this way, the simulation results are verified and the influence of factors such as bolt looseness, number of nuts, presence or absence of washers, loading frequency, and number of bolts on joint energy consumption is given. The results show that the finite element model established in this paper can effectively simulate the loosening and failure of bolts. The energy dissipation characteristics are mainly related to the structural methods of the joints. In the construction of bolted joints effective bolt anti-loosening measures should be taken to improve the energy consumption characteristics of joints.