The invention discloses a machining tool and method for slender shaft type parts. The machining tool comprises a machine frame, a left spindle box, a left tail clamping and pulling mechanism, a left tool rest, a left tool following mechanical hand unit, a left X axis transmission unit, a left Z1 axis transmission unit, a left Z2 axis transmission unit, a left chip removal mechanism, a right spindle box, a right tail clamping and pulling mechanism, a right tool rest, a right tool following mechanical hand unit, a right X axis transmission unit, a right Z1 axis transmission unit, a right Z2 axis transmission unit and a right chip removal mechanism. The two ends of a workpiece are clamped at the same time through two sets of tailstock clamping mechanisms and a main transmission mechanism, and the tail throwing phenomenon of clamped slender parts is avoided; through the tail clamping and pulling mechanisms, tool following mechanical hands solve the problem that clamping rigidity of slender parts is not enough, and part machining precision is guaranteed; machining is carried out at the same time through two sets of executing devices, and the requirement for clamping force is lowered through the main cutting force equivalent counteraction principle; the purpose of obviously improving productivity is achieved.