Provided is a thin-layer chromatography sample application needle with supporting feet. An opening enabling a cavity of a sample application needle tube cannula to be communicated with outside is formed in the upper end of the sample application needle tube cannula in the axial direction, an opening hole allowing a sample application needle head to penetrate through is formed in the lower end of the sample application needle tube cannula in the axial direction, the outer side of the sample application needle tube cannula is provided with a thread, a sample application needle tube is installed inside the sample application needle tube cannula, and the sample application needle head penetrates through the opening hole in the lower end of the sample application needle tube cannula; the inner side of a support ring is provided with a thread matched with the thread on the outer side of the sample application needle tube cannula, the support ring is installed on the outer side of the sample application needle tube cannula, the support ring is connected with the sample application needle tube cannula in a threaded and screwed mode, supporting arms are connected to the outer side of the support ring, one supporting foot is connected to each support arm in the direction perpendicular to the support arm, and the sample application needle tube cannula is provided with an observation window and a measurement scale. The thin-layer chromatography sample application needle can solve the problem that sample application force is difficult to control and can prevent a sample application needle from piercing a coating layer on a chromatographic sheet; the distance between the sample application needle head and the chromatographic sheet is controlled by rotating the support ring, and it is guaranteed that sample application is accurate.