Portal crane limit safety device

The utility model relates to a portal crane limit safety device, and belongs to the technical field of ship repair and construction. The portal crane limit safety device comprises a travelling mechanism (1), wherein the middle part of the travelling mechanism (1) is provided with an installation bracket (2); the installation bracket (2) is provided with a limit switch (3); a safety collision block (4) is arranged below the limit switch (3), and the safety collision block (4) comprises a bottom plate (4.1); the bottom plate (4.1) is fixed with the ground, and the bottom plate (4.1) is provided with a lug boss (4.2). The portal crane limit safety device disclosed by the utility model can not only play a safety limit role, but also not influence the vehicle passing.