The invention discloses a vehicle tail door support rod bulb clamping spring pressing method. The method comprises the following steps: 1) a clamping spring is arranged in a clamping spring positioning groove on a slide block; a bulb is arranged on a screw rod of a fixed base; and a clamping spring expansion block is positioned between the slide block and the bulb, and is bonded with the bulb; 2)a cylinder works to drive the slide block to move to the bulb; 3) the clamping spring in the slide block is firstly contacted with the clamping spring expansion block for expansion; and the slide block continuously shifts the clamping spring to sleeve the bulb; and 4) the clamping spring expansion block is deviated from the clamping spring; and the clamping spring is rebounded to clamp on the bulb. The cylinder is controlled to work to push the slide block to slide to automatically finish assembly without needing manual assembly, so that the assembly is convenient, and the assembly efficiencyis greatly improved.