Abstract: Disclosed is a warpage suppressing reflow oven, which comprises a reflow oven body, where a perforated steel plate circulating device comprising a perforated steel plate is disposed at a reflow-oven inner oven. A plurality of downdraft modules is arranged in the perforated steel plate, and the downdraft acting forces thereof face the upper panel. More than one air extractor is communicated with the plurality of downdraft modules via a plurality of pipelines. Under actuation of the air extractors, the downdraft modules generate downdraft acting forces to the bottom surfaces of the products, so that the products are flatly attached to the universal perforated carriers without warpage in a heat soldering process. Thereby, more uniform heating of the products and better contact of solder joints and effectively improving the yield of reflow soldering operations are achieved.