Abstract: Electrohydrodynamic jet 3D printing is an emerging and promising technology of microand nano-scale additive manufacturing with a low cost and high resolution, as well as a wide range of printed materials. However, due to the high printing speed and small standoff height between the nozzle and the substrate, it is especially difficult to directly observe and measure the printed patterns. Furthermore, there are many process parameters that affect the printing accuracy and quality, among which each parameter is coupling and interacting. This paper proposed a method of controlling the accuracy and quality of printed patterns based on the regulation of the shape and size of the Taylor cone by varying the process parameters. A theoretical model was then derived and established that describes the relationship between the line width printed with process parameters, printed material, and used substrate. Through the systematic experimental study, the influences and rules of the printing process parameters on the Taylor cone and printed patterns were revealed; Furthermore, the ideal jet printing window for the same nozzle was optimized. Finally, the feasibility and validity of the experimental results were demonstrated by the typical engineering cases, and a pattern of minimum line width of 3 μm was achieved with the nozzle diameter of 60 μm. The proposed method and experimental results provide a basis for further improving the accuracy, quality, and stability for electrohydrodynamic jet 3D printing, and the method offers a feasible solution for simplification and easy operation of actual 3D printing.