Dedendum fillet curve is an important factor that affects gear bending capacity and formed by tool conjugation.Consequently,it has great significance on improving bending capacity that the gear machining and top profile of gear cutter are researched. Given different gear machining,addendum coefficient and modification coefficient,the model of corresponding transition curve was established in order to improve bending load capacity of gear. The effect of gear machining and top profile of gear cutter on bending load capacity was investigated with broken-line section method and theoretical analysis was validated by finite element method. Applying the proposed model to the example gear,under the high modification the gear bending capacity machined by rack cutter with single arc is superior to that machined by rack cutter with double arc and pinion type shaper cutter,when the gear geometrical dimensions remain unchanged; the bending capacity of gear machined by pinion type shaper cutter with single arc is superior to rack cutter under the angular modification with modification coefficient of pinion being zero.