Objective In this study, the effect of a reinforcing and reducing method of acupuncture described in nine needles and twelve yuan of lingshu, that effected on the interstitial fluid pressure in subcutaneous connective tissue of mini pigs was observed, and the biomechanical mechanism of regulating the tissue fluid was discussed. The first of the reinforcing and reducing method of acupuncture is recorded at the beginning of the Miraculous Pivot. In this study, we observed the effect of this method on the IFP of the skin in minipigs, which discussed the objective law and mechanism of regulating the interstitial fluid. Methods The manipulation technique was explained in contemporary Chinese language. Then, 9 healthy minipigs were randomly selected for reinforcing (press or bring up) and reducing (wave a big pinhole) and testing on the soft skin tissue of abdomen. In the normal state (divided into BT group, BA group, BD group, and XF group, XD group), the low fluid volume state (LVS) formed by extracting of interstitial fluid (divided into DT group, DA group and DC group) and the high fluid volume state (HVS) by injecting saline solution (divided into GX group and GD group), the IFP was testing before and after acupuncture. Results In the normal state, bringing up and pressing the needle could increase IFP , and reducing method could decrease it(P＜0.01) which could increase the rate of descent in 5 min after needling. In LVS, it increases in DT group and DA group(P＞0.05). However, in 10 min after needling, the rate of descend of IFP in these two groups are slower. In HVS, that of GX group is significantly lower than GD group (P＜0.01), and the changing trend in 5 min after needling is different. Conclusion This method, as recorded in nine needles and twelve yuan of lingshu, can increase or decrease IFP, which proves that the acupuncture method can regulate the interstitial fluid pressure in the opposite direction.