Hydrate formation and deposition in multiphase flows in pipelines can cause flow barriers and affect normal oil and gas production and transportation operations. Based on the characteristics that hydrates are easily formed in water droplets entrained in the gas phase or on the pipe wall in the gas?dominated system of the horizontal annular flow, a hydrate deposition model of the gas?dominated system with different water contents in the pipe wall was established, and the hydrate deposition rule under different influence factors of horizontal annular flow conditions were analyzed. The results show that the hydrate deposition rate increases with the water content and undercooling increased on the pipe wall in the horizontal annular flow. The deposition rate can increase three times of the original one, and the risk of hydrate blockage increases. Hydrate deposition from condensed water increases with time. This study can provide theoretical reference for subsequent related hydrate blockage and hydrate prevention and control, and has important application value.