The general model of distributed parameter switched systems (DPSS) was presented via operator semigroup theory in Hilbert. The problem of output feedback stabilization for DPSS was studied and an exponentially stable observer for any switched law was designed. Meanwhile, a switching strategy and sub-controller, which depend on the observer value, were designed and the sufficient condition of exponential stability of closed-loop DPSS was obtained. When the switching interval time is constrained, the stability analysis for DPSS was also studied via mild solution of an abstract evolution equation and the switching law and sub-controllers were also designed to guarantee that the closed-loop system is exponentially stable.