The invention discloses a method for deep-space X fluorescence analysis, which relates to X fluorescence analysis technology and uses simulative standard sample for quantitative analysis of fluorescent data of deep space planets when no actual standard sample is available. Combining with a Monte CarLo method and a fundamental parameter method, the method comprises the following steps: using x-rays, measured by a solar monitor, radiated from the sun at different times as an excitation energy spectra; adopting a geant2 software package to simulate the fluorescence spectra of different samples by using the Monte CarLo method; performing the iterative computation of fluorescence energy spectra measured in orbit and a standard energy spectrum obtained by simulation by using programs complied on the basis of the fundamental parameter method; and meshing data according to ephemeris data and field coverage design of a probe to obtain the distribution data of elements of the planets. The method of the invention avoids carrying a standard sample, but uses the Monte CarLo simulation method to obtain a simulative standard sample energy spectrum conveniently and accurately. The fundamental parameter method is an accurate computational method. The accurate distribution data of the elements of the planets can be obtained by combining the Monte CarLo method and the fundamental parameter method.