Objective to investigate the effect of progressively decreasing vacuum sealing drainage （VSD） on wound healing of severe soft tissue injuries. Methods Totally, 79 patients with severe soft tissue injuries were randomly divided into an intervention group （n=40）, and a control group （n=39）. Both groups were given VSD drainage after thorough debridement. The negative pressure value of the intervention group decreased progressively: in the early stages when the injuries were limited to soft tissue, or when the wounds produced much necrotic tissues or exudate the pressure was set between -0.06--0.08 MPa; afterwards the pressure was tailored to -0.02--0.04 MPa, except when the wounds produced much infectious exudate and unable to be siphoned out. The negative pressure in the control group was maintained between -0.06 and -0.08 MPa. The volume of drainage, changes in wound size, wound cleaning time, wound healing time, and the incidence rates of complications such as blockage, bleeding, pain and infection were compared between the two groups. Results There were significant differences in incidence rate of bleeding, and pain, and in changes in wound size and wound healing time between the two groups （P＜0.05 for all）, whereas there was no statistical significance in the incidence rates of blockage and new infections, and in drainage volume, and wound cleaning time （P＞0.05 for all）. Conclusion Progressively decreasing negative pressure has advantages over routine VSD as in thorough drainage, reducing pain and bleeding, and promoting wound healing.