This paper is concerned with stochastic stabilization problem for networked semi-Markovian jump systems with randomly occurring uncertainties and nonlinearities under event-triggered scheme. By employing the delay system method, the stochastic stability analysis and controller synthesis for semi-Markovian jump systems considering the effect of network-induced delay are presented. In order to reduce the frequency of data transmission and save network resources, sampled-data-based event-triggered scheme is utilized. Mode-dependent Lyapunov-–Krasovskii functional candidate is constructed and free-weighting matrix method is employed which can reduce some conservativeness of the results. Then, novel conditions are formulated to ensure the stochastic stability for stochastic semi-Markovian jump time-delay systems in terms of linear matrix inequalities(LMIs). Controller gain matrices and event-triggered matrices can be co-designed simultaneously based on the obtained sets of LMIs. Finally, simulations are given to illustrate the effectiveness of the results.