Abstract: Traditionally, the determination for trace Se by the method of hydrogenide producing and atomic fluorescence spectrum adopts the complex mineral melting way, that is, melting the minerals with versa aqua regia and, and then detecting after the smoking of perchloric acid under low temperature. It is both time-consuming and waste of agent. In the method introduced by this paper, Se is detected in the solution that is for Bi testing. By the verification for the testing limit, precision and recovery rate, the result is satisfactory. This method can measure the contents of Bi and Se at the same time by melting minerals once, with simple and quick operation, less interference, high sensitivity and stable and reliable results. It is also agent saving, suitable for combined testing of Bi and Se in batch of geochemical samples.