Saxifraga tangutica is widely used as a medicinal herb to treat hepatic diseases. Here, we developed a class separation method to separate gallic acid derivatives 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors from the methanol extract of Saxifraga tangutica. Firstly, an MCI GEL CHP20P medium‐pressure liquid chromatography was used to pretreat the crude extract from Saxifraga tangutica (500 g) and the target sample (fraction Fr1, 1.7 g) was obtained. Then, an online reversed‐phase liquid chromatography–1,1‐diphenyl‐2‐picrylhydrazyl assay was employed for recognizing potential 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors and six 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors fractions were recognized from fraction Fr1. Subsequently, the six 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors fractions were isolated via a ReproSil‐Pur C18 AQ preparative column. During the separation process, the hydrophilic liquid chromatography was used to enrich the target compounds (Fr1‐3‐1‐1 and Fr1‐3‐1‐2) from the fraction Fr1‐3, which were hardly isolated only by one step reversed‐phase liquid chromatography. Finally, six gallic acid derivatives were obtained and identified as gallic acid (Fr1‐1‐1), gallic acid 3‐O‐β‐D‐glucoside (Fr1‐1‐2), protocatechuic acid (Fr1‐2), 4‐O‐galloyl‐(‐)‐shikimic acid (Fr1‐3‐1‐1), 5‐O‐galloyl‐(‐)‐shikimic acid (Fr1‐3‐1‐2), and 3‐O‐galloyl‐shikimic acid (Fr1‐4), respectively. Thus, the present study indicated that this method was highly efficient for the preparative separation of gallic acid derivatives 1,1‐diphenyl‐2‐picrylhydrazyl inhibitors from natural products.