Due to the large specific surface area and high surface energy of potassium titanate whiskers, they are easier to agglomerate, which will affect the dispersion of composite materials. Therefore, it is necessary to modify the surface of potassium titanate whiskers. By designing orthogonal experiments with three factors and three levels, the performance of sealing gaskets prepared by potassium titanate whiskers modified by different silane coupling agents, concentrations and coupling reaction time, was studied, and the optimal surface modification method of potassium titanate whiskers was obtained. The results showed that when the coupling reaction time was controlled for 1 h and the mass fraction of KH-560 coupling agent was 3%, the dispersion effect of potassium titanate whiskers after surface treatment was better, and there were more attachments on the surface. Moreover, the reunion situation is relatively mild , and the adhesion was also greatly improved, the potassium titanate whisker obtained by using the optimal surface modification method will be used in the preparation of asbestos free gaskets, the obtained asbestos-free sealing gasket has a compression rate of 18.169%, the rebound rate reached 47.226%, and the tensile strength reached 13.803 MPa. Compared with non asbestos sealing gaskets without adding potassium titanate whiskers, the tensile strength of non-asbestos sealing gaskets can be improved to a certain extent.