Abstract: Watermelon grafted rootstock can be damaged when it is fixed and treated before the growth point is removed. In order to solve these problems, it took gourd seedlings as the test object, and on the basis of analyzing its physical characteristics, a rootstock clamping and seedling pressing mechanism was designed. The mechanism was completed the clamping and loosening of rootstock seedlings through the expansion and contraction of the air bag, which could effectively solve the problem of seedling damage in the traditional clamping mechanism. At the same time, it was adopted forward and backward symmetrical double roller seedling pressing mechanism, which could solve the problem that cotyledon root was easy to break in the process of seedling pressing. The static analysis and ADAMS based kinematics simulation of the seedling pressing mechanism were carried out. After analyzing the damage caused by the impact force to the rootstock seedling, it could be known that when the cylinder speed was 40～60 mm/s, the displacement curve of the rear pressure roller was relatively stable without obvious fluctuation. According to the clamping and seedling pressing tests of 150 calabash seedlings, the damage rate of both clamping and seedling pressing was 0%. The rootstock clamping and seedling pressing mechanism is reasonable, which can provide reference for the design and research of vegetable grafting machine.