The invention relates to a Stauntonia brachyanthera Hand-Mazz component as well as a preparation method and application thereof, belonging to the technical field of medicines. The method comprises the following steps of: extracting Stauntonia brachyanthera Hand-Mazz by using water or organic solvents with different concentrations, filtering and recovering the solvents to obtain a concentrated solution; eluting the concentrated solution by using water and an organic solvent through macroporous absorption resin, recovering the solvent to obtain a saponin, or obtaining the saponin from an n-butyl alcohol layer by using an extracting method; then further separating and purifying the saponin by using a normal-phase silicagel column, a reversed phase column and a high efficient liquid phase preparation system; and finally obtaining a monomer or compound with remarkable activity. The Stauntonia brachyanthera Hand-Mazz component of the invention can be singly or combined with other drugs to be used as a raw drug applied to a drug for resisting tumour, resisting inflammation, promoting urination, and treating other diseases. The Stauntonia brachyanthera Hand-Mazz component prepared with the method has high purity, remarkable pharmacological action, simple and convenient method, practicability, low price, safety, suitability for industrialized production.