Closed block for cable lay-out on tower

The invention relates to a closed block for cable lay-out on a tower. The closed block is characterized in that a vertical pulley I, a vertical pulley II and a horizontal pulley are arranged in a fixed frame; one end of the vertical pulley I and one end of the vertical pulley II are respectively connected with the two ends of the horizontal pulley; a sealing door is arranged between the other end of the vertical pulley I and the other end of the vertical pulley II; and a connecting mechanism is arranged at one side of the fixed frame. The closed block is light and flexible when used for cable lay-out on a tower. Through rotation of the three pulleys with the same radian, the problem of cable scratch is eliminated, and the quality of cable construction is improved. The vertical pulley II is a movable pulley, which can prevent a cable from popping out from the block. Moreover, the block is installed on a tower by a fixed belt, and installation is convenient and flexible.