The invention relates to an automatic assembly mechanism of an automobile inner door pulling handle spring. The automatic assembly mechanism comprises a multiplier line and a control system; a positioning pallet is arranged on the multiplier line; an inner pulling handle body is fixedly arranged on the positioning pallet; a handle assembly system, a spring assembly system and a pin roll screeningand assembling device are arranged on two sides of the multiplier line; the handle assembly system, the spring assembly system and the pin roll screening and assembling device are all connected to thecontrol system; and the control system controls the handle assembly system, the spring assembly system and the pin roll screening and assembling device to work cooperatively. By adopting the automatic assembly mechanism, full-automatic assembly operation of the automobile inner door pulling handle spring can be realized.