The invention discloses a lock catch device based on a projection support. The projection support comprises a foot support, a bar and a hanging rod, wherein the bar and the foot support are fixedly arranged, and the hanging rod is located on the top of the bar. The bar is provided with a plurality of lock catch devices. Each lock catch device comprises a hollow lock sleeve, a limiting plate and a compression spring, wherein each hollow lock sleeve is used for containing the bar, each limiting plate is fixedly arranged in the corresponding lock sleeve in an inserted mode, each compression spring is arranged between the corresponding limiting plate and the corresponding lock sleeve, each compression spring is located outside the corresponding lock sleeve, and a containing hole used for containing the bar is formed in the position, inside the corresponding lock sleeve, of each limiting plate. The lock catch device is simple in structure, convenient to manufacture, mount and dismount, and good in locating effect.