China has the largest visually impaired group around the world. There is a lack of an e-reader for blind people to learn independently. Using electrorheological(ER) fluid micro valves to manipulate Braille dots matrix has the merit of easy control with low energy consumption. The ER fluid micro valve is an important part of the Braille display. The correct display of Braille depends on the stability of the ER valve. Different valve parameters make different operating points and affect the stability of the valve. The refresh rate of the braille dots depends on the output flow of each valve under the same given pressure, and different valve gaps make different valve voltages, which affects the refresh rate of the braille dots. In this paper, based on the established mathematical model of the ER valve, the influence of the structure parameters of the ER micro valves on the stability of the valve and the transmission flow is analyzed, which provides technical support for the design of the micro valve for such applications.