Aviation spiral bevel gears are often generated by spiral generated modified(SGM) roll method.In this style,pinion tooth surface modified generation strategy has an important influence on the meshing and contact performances.For the optimal contact pattern and transmission error function,local synthesis is applied to obtain the machine-tool settings of pinion.For digitized machine,four tooth surface generation styles of pinion are proposed.For every style,tooth contact analysis(TCA) is applied to obtain contact pattern and transmission error function.For the difference between TCA transmission error function and design objective curve,the degree of symmetry and agreement are defined and the corresponding sub-objective functions are established.Linear weighted combination method is applied to get an equivalent objective function to evaluate the shape of transmission error function.The computer programs for the process above are developed to analyze the meshing performances of the four pinion tooth surface generation styles for a pair of aviation spiral bevel gears with 38/43 teeth numbers.The four analytical results are compared with each other and show that the incomplete modified roll is optimal for this gear pair.This study is an expansion to generation strategy of spiral bevel gears,and offers new alternatives to computer numerical control(CNC) manufacture of spiral bevel gears. Aviation spiral bevel gears are often generated by spiral generated modified (SGM) roll method. This style, pinion tooth surface modified generation strategy has an important influence on the meshing and contact performances.For the optimal contact pattern and transmission error function, local synthesis is applied to obtain the machine-tool settings of pinion.For digitized machine, four tooth surface generation styles of pinion are proposed.For every style, tooth contact analysis (TCA) is applied to obtain contact pattern and transmission error function.For the difference between TCA transmission error function and design objective curve, the degree of symmetry and agreement are defined and the corresponding sub-objective functions are established. Linearound combination method is applied to get an equivalent objective function to evaluate the shape of transmission error function. computer programs for the process above are developed to analyze the meshing performances of the four p inion tooth surface generation styles for a pair of aviation spiral bevel gears with 38/43 tooth numbers. These four analytical results are compared with each other and show that the incomplete modified roll is optimal for this gear pair. This study is an expansion to generation strategy of spiral bevel gears, and offers new alternatives to computer numerical control (CNC) manufacture of spiral bevel gears.