<p>Variable area turbine vanes are critical components for achieving adaptive cycles in aero-engines, essential for balancing high thrust and efficiency. The variable staggered angle turbine vanes pose challenges in achieving efficient cooling, thereby limiting their applications in high-pressure turbines. Suction-side adjustable turbine vanes can integrate efficient cooling with excellent aerodynamic performance design, potentially solving the challenge of adjusting high-pressure turbines. This paper was based on the&#xa0;VKI LS89 vane and constructed suction-side adjustable turbine vanes. Using a turbulence model named SST <i>k</i>–<i>ω</i>, it analyzed the variations in parameters such as Mass flow rate, aerodynamic losses, and flow angle at different vane openings. It also compared and studied the flow regulation capabilities and aerodynamic loss characteristics between suction-side adjustable turbine vanes and variable staggered angle turbine vanes. The results showed that within the adjustment angle range of 0° to 3°, the suction-side adjustable turbine vane had a flow regulation capability of 10.8%, while the variable staggered angle turbine vane had 15.0%. Considering leakage, the total pressure loss of the suction-side adjustable turbine vane with coolant leakage was much smaller than that of the variable staggered angle vane with end-wall gaps, amounting to only 60% of its total pressure loss. When the vane rotated by 3°, the change in the outlet flow angle of the suction-side adjustable turbine vane was only 1.5°, whereas, for the variable staggered angle vane, the change in the outlet flow angle at the blade tip and root regions was 15°. Additionally, coolant leakage near the blade tip and root regions of the suction-side adjustable turbine vane achieved better cooling efficiency.</p>