Objective To study the effect of traditional Chinese medicine ointment ironing in alleviating the local reaction caused by intravenous infusion of 20%and sum up nursing experience. Methods Fifty eight patients of acute lumbar disc patients with intravenous infusion of 20% mannitol were randomly divided into the observation group and the control group according to the simple random method with 29 cases in each group. In the course of intravenous infusion of 20%mannitol, local hot dressing was done in the observation group using traditional Chinese medicine ointment ironing properly along the direction of the blood vessel from the 2 cm puncture needle until 30 min after intravenous infusion of mannitol was finished. The control group use the concentration of 330 g/L (33%) magnesium for hot and wet dressing until 30 min after intravenous infusion of mannitol was finished. The two groups were compared in terms of pain degree and the level of phlebitis. Result The pain degree and phlebitis level in the observation group were significantly lower than those in the control group (all P<0.01). Conclusion The traditional Chinese medicine ointment ironing can effectively alleviate local pain and reduce the severity of phlebitis caused by intravenous infusion of 20%mannitol , with curative effect better than that of magnesium sulfate.