Abstract: The pore throats are narrow and fluid-solid coupling is obvious in tight reservoirs. Because the implementation results of waterflooding and gas drive are very different in different tight reservoir blocks, selecting reasonable energy replenishment modes is a difficult problem in tight oil production. The paper uses numerical simulation methods to study the effects of different energy replenishment modes for staged fracturing in tight reservoirs in horizontal wells, discusses the main controlling factors of the energy replenishment mode selection and proposes definite limits. The study shows that the difference of permeability is the key parameter to select energy replenishment mode. Compared with pore radius, pore throat radius has more impacts on permeability, which can influence the producing degree and development effect of tight oil reservoirs directly, and meanwhile, can reflect microscopic characteristics of the reservoirs, so it can be a parameter for energy replenishment mode selection. It is considered that the main pore throat radius of 1.5 μm can be used as the limit for energy replenishment mode selection in tight oil reservoirs