To improve the service performance of the dry disc brakes for tracked vehicles，a novel pressurized structure based on the taper roller is proposed and studied. The extension of generatrix is intersected with the axis of pressurized structure to guarantee the pure rolling condition for the taper roller and brake. The full arc convex and arc modified form are given to improve the mechanical performance of tapered roller. Based on penalty contact algorithm，the circular arc，tapered roller and improved types are analyzed and compared using explicit finite element method under typical brake condition. Numerical simulation results show that the stress state is great improved because the proposed roller is line contact instead of point contact of spherical billiard. The full arc convex and arc modified form can eliminate the boundary effect of roller. Not only the maximum effective stress is reduced，but also the uniform stress along axis is guaranteed for the full arc convex roller.