Objective To observe the clinical efficacy of applying Sweat Reduction Formula (SRF) externally in the treatment of cancer-linked hyperhidrosis. Methods 45 tumor patients, who exhibited excessive perspiration, were selected and recruited randomly into an experimental group (Sweat Reduction Formula group) with 24 patients in it and a control group (Placebo group) with 21 patients in it. The experimental group was treated with SRF and the control group was administrated with placebo. Neuropad diagnostic patches were used to observe the period of time that required for any visual changes in color before and after medication. These observations were then matched with the commonly seen signs and symptoms scoring table, to evaluate the changes of symptoms and KPS. Results The color changing time of the experimental group was 14.45±3.91 min. and 19.51±5.30 min. before and after medications respectively. And the changing time in the control group was 13.49±4.96 min. After medication. The results were highly significant with P<0.05. There were also different levels of significant improvements in terms of spontaneous perspiration, night sweating, dry mouth, feverish sensation over hand-foot centers and body, aversion to cold etc after the treatment in the experimental group. Conclusion It would be more objective to evaluate the clinical efficacy of applying SRF on navel to treat cancer-linked hyperhidrosis with neuropad diagnostic patches.