The invention belongs to the technical field of pipeline repair, particularly relates to an open-loop Hough section seal pad comprising two semi-arc-shaped seal rings which are arranged oppositely, and a seal strip which is used for connecting the seal rings; and both ends of the seal strip are respectively connected to one ends of the two seal rings which are on the same side. When the open-loop Hough section seal pad is used, not only can the installation stability, the high pressure resistance and the water hammer resistance of the whole seal pad be ensured, meanwhile because the number of the seal strip is reduced, the overall used amount of materials is effectively reduced, the production and manufacturing cost can be reduced, and the economic benefits of an enterprise are ensured.