Abstract: In order to meet the demand for detecting different ions of one plant material at the same time in the future, it’s of great significance to design a microelectrode array for the micro dynamic ion flow detection of plant. This paper introduces a microelectrode array for the ion flow detection based on Fick’s law. The microelectrode array is composed of microelectrode, electrode holder, fixed link of array, array framework, silver thread, wire, signal amplifier, etc. Compared with the previous ion flow signal detection electrode, the microelectrode array is characterized by detecting different ions at the same time with diversified forms and high efficiency. It’s found through the detection experiment of nine ions like K+ and NH4+ in the maize root tip that: the microelectrode array can meet the demand fordetecting different ions at the same time. In addition, with the characteristics of high efficiency and small error, it can describe the growth of plants more accurately.