Abstract: In the process of electrical stimulation of biological tissue, the crucial point is that the bioimpedance between the stimulation electrodes are within the load range of the stimulator. In this paper, the STM32 system and AD5933 impedance measurement chip are used to form an bioimpedance detection device, and electrical stimulation and impedance testing are carried out on the biological tissue simulated by agarose gel and 3D printing mold. The experimental results show that the change of electrode position has a great influence on the bioimpedance between electrodes, so that it is quite necessary to monitor the bioimpedance between electrodes for long-term electrical stimulation experiments where the electrode position is easy to move.