In this paper, we discuss the adaptive output feedback control problem for switched stochastic nonlinear systems which involve uncertain time-varying parameters and unknown output functions. The drift terms together with diffusion terms meet the conditions for linear growth with unknown rate. Firstly, an adaptive output feedback controller is proposed based on the backstepping method. Then, by using the stochastic Lyapunov stability theorem, all signals of the closed-loop system are proven to be bounded in probability and the system states are almost certain to reach the origin under arbitrary switching. Finally, a numerical example is provided to test the reliability of the proposed method.