Objective To design a occluder suitable for anal fistula internal mouth closure surgery, study the structural design of the occluder and the interaction between implant and tissue, and evaluate the performance of internal mouth closure. Methods Design and model the overall structure of implant and occluder; The finite element model of plugging was established to study the stress distribution and damage area of tissues during plugging; Build a tissue puncture experimental platform to verify the simulation model and results; The pull-out force test platform was built to evaluate the sealing effect of the internal opening. Results During the plugging process, the maximum torque of the feeding mechanism is 0.036 N · m, the maximum stress of the tissue is 19.75 MPa, and the damage area is 1.35 cm2; The finite element model is basically consistent with the experimental results; The maximum pull-out force reaches 5.11N. Conclusions The area of tissue damage in the process of occlusion meets the requirements of minimally invasive treatment of anal fistula; The minimally invasive anal fistula occluder designed in this paper can effectively block the internal mouth , which is helpful for doctors to perform minimally invasive surgery for anal fistula more conveniently, quickly and effectively.