The aerodynamic characteristics of the vertical tail of an aircraft are directly related to the size and weight of the vertical tail. Increasing the lift force of the vertical tail using flow control can further reduce the size of the vertical tail, which has practical significance for reducing the weight of the structure. In this paper, the CFD method is used to numerically simulate the active flow control of vertical tail using the co-flow jet technique. The influence law of jet momentum coefficient on continuous co-flow jet and the influence law of jet momentum coefficient, blockage ratio, injection hole number on discrete co-flow jet is studied. The results show that for the continuous co-flow jet, with the increase of jet momentum coefficient, the effectiveness of lift enhancement, drag reduction and separation suppression becomes more significant. When the jet momentum coefficient reaches 0.14, the lift coefficient is nearly twice that of the baseline vertical tail, which means that the vertical tail size can be reduced by about 50%. For the discrete co-flow jet, compared with the continuous co-flow jet, the effectiveness of lift enhancement gradually decreases with the increase of the blockage ratio, and the power consumption also decreases at the same time. An appropriate blockage ratio can produce better comprehensive control effect. For the model and flow condition in the present study, with the increase of the discrete hole number, the lift enhancement effect first increases and then decreases. When the injection hole number is 5, the lift coefficient reaches the maximum. When the number of nozzle is 20, the comprehensive aerodynamic efficiency considering energy consumption is better.