In the fluidic amplifier of a nozzle-flapper servovalve, the inner flow channel which in a minimized size is under a high pressure condition. The working performance of nozzle plays an important role in the static, dynamic characteristics and the working stability of servovalve. In this article, we focus on the nozzle jet performance, with comparison between CFD simulations and experiment results. Both results prove the initial inlet flow angle and the distance from inlet to outlet influence the jet-flow greatly. Then we provide optimizations of the nozzle design principles in order to improve the performance of fluidic amplifier and the servovalve.