This paper investigates the stationary distribution and extinction of a stochastic population model with Allee effect and nonlinear perturbation. The author first proves the existence of global positive solution of the model. Then by constructing a suitable stochastic Lyapunov function, the author establishes sufficient conditions for the existence of an ergodic stationary distribution of the model. Then the author obtains sufficient conditions for extinction of the population in two cases. One is how Allee effect affects extermination of the population and the other is how noises affect extermination of the population. At last, some examples together with numerical simulations are provided to illustrate the analytical results. }