A display with an automatic locking device. The display includes a body, a support, and a sliding assembly. The support is connected to the body. The base connects with the support in a rotatable manner. The sliding assembly is movably disposed on the base in a manner such that the sliding assembly can move between a first position and a second position. When the sliding assembly is in the first position, the support is separated from the sliding assembly. When the sliding assembly is in second position, the support is engaged with the sliding assembly.