The invention provides a method for simultaneously determining trace gold, silver and palladium in a geochemical sample. The method comprises the following steps: firstly, digesting the geochemical sample by using 1:1 chloroazotic acid in a constant-temperature boiled water bath in a sealed manner; secondly, selectively enriching the trace gold, silver and palladium by using diphenylthiourea loaded polyurethane foam, and separating other interference elements; and finally, drawing a standard curve of Au197, Ag107 and Pd105 by adopting an inductively coupled plasma source mass spectrometer through a standard curve method, and simultaneously determining the trace gold, silver and palladium in the sample. According to the method provided by the invention, the problem that other main interference elements with the abundance of geochemical elements, which is hundreds, even thousands of times of that of the silver and the palladium, have interference on mass spectrums of the silver and the palladium is solved; and compared with a traditional emission spectrum and graphite furnace atomic absorption spectrometry, the sampling amount in analysis of the silver in the geochemical sample is increased by dozens of times, so that the influences caused by gold grain effect of the geochemical silver are effectively overcome.