The invention relates to a rope ladder head with a self-locking device, which belongs to the technical field of overhead transmission line maintenance. The technical solution of the rope ladder head is characterized in that a front main bracket (1) and a back main bracket (10) are parallelly arranged; the front main bracket (1) is fixedly connected with the back main bracket (10) through a plurality of crossbeams (12) which are parallel with each other; a back line extending wheel (33) is arranged between the back main bracket (10) and a back auxiliary bracket (31); the back main bracket (10) is fixedly connected with the upper end of the back auxiliary bracket (31) through a back connecting beam (32); an opening is formed between the back main bracket (10) and lower end of the back auxiliary bracket (31), thereby forming a sealing door; the sealing door is internally provided with a self-locking tongue plate (8); a tongue plate locking spring is arranged between the self-locking tongue plate (8) and the back main bracket (10); and a self-locking tongue plate head restraint (6) is arranged above the self-locking tongue plate (8). The rope ladder head with the self-locking device has a beneficial effect of preventing rope ladder falling from a high position and human body injury caused by falling of the rope ladder head from a grounding line in a process of climbing the rope ladder by personnel.