The miniaturization of electronic devices requires a decreasing quality of adhesive points. In order to obtain the minimum defect free adhesive point for injection, this paper uses a combination of Taguchi experiment and CFD method to systematically study the influence of structural changes in the needle nozzle on the mass size of the adhesive point of the piezoelectric injection valve. The results indicate that the structural changes of the needle nozzle have a significant impact on the quality of the sprayed adhesive point. For the five types of needle and nozzle structures studied, when the nozzle size is 0.05mm and the needle size is 1.0mm, the adhesive produced by the injection valve is the smallest, and the minimum adhesive mass is 13.3% of the original injection valve (APJ1500) injection mass. Through CFD simulation, it was found that due to the smaller nozzle diameter of the optimal parameter combination during the valve opening stage, and the higher reflux ratio of the nozzle combination during the needle lowering stage, it can produce smaller adhesive mass.