The invention relates to the field of movable type ultra-high-layer structure movable arm tower cranes used for building construction, in particular to a restraining structure for an end head of a girder of a movable type movable arm tower crane and a demounting and mounting method of the restraining structure. The restraining structure for the end head of the girder of the movable type movable arm tower crane comprises backer plates and a latch structure. The backer plates include the first backer plate and the second backer plate, wherein the first backer plate and the second backer plate are fixedly arranged on the upper end face of an embedded part, and a gap is formed between the first backer plate and the second backer plate and used for containing the girder of the movable arm tower crane. The latch structure is located at the upper end of the girder of the movable arm tower crane, and the two ends of the latch structure are matched with the first backer plate and the second backer plate correspondingly and used for fixing the girder of the movable arm tower crane. The restraining structure of the end head of the girder of the tower crane is welded in a factory, the links such as cutting of a steel plate in a traditional method are omitted in the demounting process, the field workload is reduced, efficiency is improved, and the restraining structure of the end head of the girder of the tower crane can be rapidly demounted on the basis of ensuring the stability of the girder of the tower crane.