The utility model provides a coating machine drying oven and tuyere thereof, tuyere are used for blowing in order carrying out the drying to the substrate to the substrate behind the coating, including air -out device and return air device, the air -out device has air inlet end and air -out end, the air -out device is equipped with double -phase right air -out curb plate, and each air -out curb plate is buckled to another air -out curb plate respectively in the air -out end and is formed with the air -out panel, the return air device stretches into in the air -out device, the return air device is equipped with the return air panel in the one side towards the substrate, and it has a plurality of return air holes to open on the return air panel, and on return air panel length direction, the trompil region and the open hole area in return air hole diminish by narrowing down gradually to both ends in the middle part of the return air panel, the both sides of return air device respectively and have the clearance between the scene 2 windpiston board of air -out device to air -out end relief at the air -out device becomes the scene 2 wind gap, the tuyere forms the torrent district between scene 2 wind gap, return air device and the substrate when drying to the substrate through the air outlet. The utility model discloses the drying effect of tuyere to the substrate has been optimized.