A novel ease-off flank zoning modification method was proposed to pro-control the meshing performance of spiral bevel gears manufactured by duplex helical method. The conjugate pinion tooth surface was modified to meet the preconditions, which was generated by gear theoretical tooth surface, and then the conjugate pinion tooth surface was divided into three regions, i.e., the toe, the middle and the heel. These regions' modification with three segment parabolics were conducted along the contact path and the contact line. Ease-off tooth contact analysis methodology was used to analyze the target tooth surface meshing performance. The results show that the transmission error, contact path and contact line are the same as the pre-preconditions. The novel zoning modification method can be used for modification research of whole tooth surface of spiral bevel gears manufactured by duplex helical method.<br/> ©2018, Central South University Press. All right reserved.