The lift fan is a critical component in vertical short takeoff and landing (VSTOL) fighters, enhancing thrust and offering significant applications in aerospace. To streamline airflow and optimize flow field distribution, guide vanes are often incorporated into lift fans to improve efficiency. However, studies on the aerodynamic impact of inlet and outlet guide vanes remain limited. This research examines the effects of inlet guide vane number and deflection angle, as well as the influence of outlet guide vanes on flow characteristics, using a two-stage counter-rotating lift fan as the subject. Findings indicate that fan lift increases steadily with the number of inlet guide vanes until reaching ten, after which additional vanes cause a rapid decrease in lift. The total pressure loss coefficient initially remains constant and then rises with increased inlet guide vane deflection angle. As adjustable vanes, the inlet guide vanes can pivot from approximately 80° to 20° to achieve gradual lift improvement. Compared to configurations without outlet guide vanes, the addition of outlet guide vanes significantly enhances airflow uniformity near the fan’s exit, reducing aerodynamic losses and stabilizing the overall flow.