The present invention discloses a quick molding method of a test article of a drip irrigating belt with thin wall. The method is that a plastic film is sent into a labyrinth-structure molding device of an irrigator by a directive wheel and a step drawer roller to make the plastic film form an irrigator labyrinth-structure at the labyrinth-structure molding device of the irrigator, then the marginal seams of the plastic film which formed a labyrinth flow channel are welded to form the drip irrigating belt. The method of the present invention simplifies the difficulty of the molding technology, reduces the developing cost and greatly shortens the developing period; the method adopts an intermittent vacuum plastic-absorbing labyrinth flow channel and the seam welding technology; the design and development is provided with a quick molding test device of the drip irrigating belt with a high degree of automatization and can continuously process the drip irrigating belt of 100 meters; the cost of a mould is not more than 500 Yuan; the developing period is about one week; the method can be carried out just within an laboratory.