Traditional sealing technologies, such as packing seals, have limitations, such as excessive wear and heat generation from friction, which limit their usefulness in an age where increasingly complex machinery need a more robust sealing effect. Based on a theoretical analysis of the instability at the liquid-liquid interface and the pressure resistance of the seal structure, while also factoring in the angular velocity of the shaft, this study reconstructs the formula for estimating the pressure resistance value of the seal structure. The magnetic fluid seal's design is based on the high horizontal shaft diameter while submerged in liquid. We can calculate the strength of the magnetic field within the magnetic fluid seal and how it varies with the size of the permanent magnet and the width of the pole teeth using the Maxwell magnetic field analysis programme. The ring seal test apparatus was used to conduct a pressure test on the seal structure of the horizontal big shaft diameter at different rotational speeds to determine the structure's efficacy. The findings are both theoretically and practically significant for the development and implementation of magnetic fluid seal structures.