The Liaodong oak (Quercus wutaishanica Mayr) is dominant in the composition scheme in Qingyang City, and its growth performance and management practices have long been central concerns of forest management. However, the long cycles and complex dynamics of forest development make accurate prediction difficult, thereby constraining the design of optimal silvicultural strategies. To remedy the slow growth and suboptimal timber quality of Q. wutaishanica plantations—while fostering large-diameter trees, increasing merchantable yield and the output of high-value timber, and enhancing forests’ carbon-sequestration and oxygen-release services—there is an urgent need for a rigorous predictive framework. Using data from the sixth, seventh, and eighth National Forest Resource Inventories, we developed a transition-matrix growth model comprising growth, ingrowth, and mortality sub-models. With this model, we selected representative plots and simulated 25-year trajectories of stand diameter-class structure and growing stock under three climate scenarios (RCP2.6, RCP4.5, RCP8.5). Results indicate divergent trends in growing stock among scenarios; under RCP2.6, stands attain higher growing stock, a more balanced diameter-class distribution, and a markedly larger number of large-diameter trees. Moreover, Q. wutaishanica exhibits relatively stable growth throughout the simulation horizon. Overall, the transition-matrix model effectively captures short-term stand dynamics, fills a regional research gap for Qingyang City, and provides a robust evidence base for subsequent science-based forest management.