The invention relates to a triggering part for unlocking and a body frame plate with an unlocking function, wherein, the triggering part is used for triggering the unlocking by adopting a foot or legof a patient; The body frame plate comprises the triggering part; The triggering part and the body frame plate provided by the invention, The invention has the advantages of reasonable structure and low manufacturing cost, and is suitable for patients of different heights, so that the radiotherapy patient lying flat and fixed on the body frame plate can trigger and unlock by his own foot or leg, not only effectively avoiding the drawbacks in the prior art, but also enabling the patient to trigger and complete the unlock more conveniently, more easily and more efficiently.