In this paper, we consider a two‐species generalist predator–prey model in closed advective environments. Compared with the model in open advective environments to the generalist predator–prey model, the dynamics of our system are different. It is easy to verify that the generalist predator can always invade. Meanwhile, we provide the dynamical behaviors of the model in terms of the intrinsic growth rates, the carrying capacity of both species, the predation rate, and the trophic conversion efficiency. More precisely, we establish the local/global stability of the semi‐trivial steady states and a unique positive equilibrium for the model.