Braided rope is one of the important devices for power transmission in land-based high altitude wind power generation, connecting the high altitude wind catching parachute ladder and the ground equipment, which is in periodic contact with the drum bending and constantly generating frictional heat energy. In order to predict the frictional heat energy loss generated by the braided rope, a numerical modelling method for 12-strand braided rope-drum was proposed, which was based on the principle of the pore-containing RVE (representation volume element) model, and realized the modelling of the rope from the fine fibre to the macroscopic braided rope; and the frictional heat generation law generated in the process of power transmission of the braided rope-drum was investigated. The frictional heat generation law in the process of braided rope-drum power transfer was investigated, and the frictional heat generation mechanism of braided rope in land-based high altitude wind power system was revealed. The results show that the friction energy dissipation of braided rope decreases with the increase of drum radius, and the proportion of friction loss caused by bending of braided rope during power transmission is 0.62% ~ 4.3%.