The invention discloses a starting seal replacement method in pipe jacking construction. The starting seal replacement method comprises the following steps of (1) filling, (2) detaching of a replacement part, (3) removing of a used seal device, (4) replacing of a new starting seal, (5) mounting of the sealing device and (6) resetting of pipe segments. The starting seal replacement method has the advantages of being convenient to operate, high in replacement efficiency and low in cost; and by adopting the starting seal replacement method, the starting seal can be replaced rapidly, the loss of thixotropic slurry is reduced, jacking friction force is reduced, the cost is low, the efficiency is high, and the quality is reliable.