As common regulators, window-type sleeve control valves are critical components in process industry systems and the core structures of the control system flow. However, the occurrence of cavitation within these valves can lead to issues such as the failure of control capabilities and the wear of the structural surfaces, which can significantly affect the normal flow regulation of the system. In the design process of window-type sleeve control valves, there are two symmetrical installation angles of the sleeve based on engineering practice. This work aims to elucidate the impact of sleeve angles on the cavitation characteristics of window-type sleeve control valves. Numerical simulation methods are employed to investigate the cavitation characteristics and the cavitation mechanisms under different sleeve angles and various operating conditions. The results indicate that changes in the sleeve angle can effectively suppress cavitation within the valve without compromising its flow capacity. Two different sleeve angles are investigated in this research. Under high-pressure drops, the maximum growth rate of the steam phase volume reached 40.29%, while the growth rate of the valve's resistance coefficient is below 5%. This finding means that adjustments to the sleeve angle can be made to minimize cavitation while maintaining the valve's flow capability. Furthermore, the research identifies two distinct mechanisms of cavitation generation within the valve: one resulting from high-speed jets due to abrupt area contractions and the Coanda effect, and the other caused by local pressure drops associated with strong vortex structures at the bottom of the throttling window. Interestingly, a direct correlation is found between the presence of these strong vortex structures and the locations where cavitation occurs. The findings of this study provide valuable insights for setting the sleeve installation angles and optimizing the design of cavitation suppression structures in window-type sleeve control valves, enhancing their performance and reliability in engineering applications.