A kind of fresh food packaging machine based on the negative pressure type was designed in view of high labor intensity and low production efficiency due to artificially packaging. The packaging machine consisted of transverse sealing device, cutting mechanism, film feeding mechanism, vertical sealing device, and so on, which was suitable for many kinds of fresh food packaging. And the structure and working parameters of the device for negative pressure type fresh food packaging machine was studied. According to the FLUENT analysis of the inner flow field of rear air suction box, the box adopted cross section of rectangular box type. And the cross sectional parameters were 25mm and 64mm. The belt conveyor was adjusted by the eccentric roller to ensure that there was sufficient pressure between the upper belt and the lower belt. Meanwhile, by using the virtual prototype of ADAMS, the influence of main parameters on motion of the mechanism was obtained. The prototype test showed that the packaging speed was 49.4pack/min, the packaging rate was 99.4%, and the swell rate was 5%, which indicated that the fresh food packaging machine could satisfy operation demand of the enterprises engaged in processing fresh food. The fresh food packaging machine with negative pressure type met the design requirement and anticipated goal.