This paper studied and modified the FR300 dryer of the gravure printing machine so as to provide an optimal solution of model improvement for the enterprise. The numerical simulation method was used to establish the three-dimensional physical model of drying oven. The oven velocity field, pressure field and temperature field were studied. The hot air flow trace map and the section map of the drying oven were obtained. In respect to the features of internal heat flow and the structural characteristics of the drying oven, the vent structure of the drying oven was modified and the new structure of the oven was determined. It was showed that the effect of the improved oven on drying prints was better, and the outlet pressure was smaller（-330 Pa and -150 Pa） , which was more conducive to the selection of the negative pressure blower. The results provided a strong reference for the researches of structural design and improvement of drying oven.