Toolpath topology design based on vector field of tool feeding direction in sub-regional processing for complex curved surface

•Sub-regional toolpath topology design method based on vector field is proposed.•Bi-objective optimization model with constraint of machining errors is established.•Surface segmented criterion based on vector field is devised for machining quality.•Surface subdivision based on kinematics performance of machine tool is carried out.•Machining accuracy is improved greatly in high-efficiency sub-regional processing.