The invention relates to a method for measuring the concentration distribution of compositions in a particle-fluid two-phase flow reactor. The method comprises the following steps of: S1, calculation of the
mass conservation equation and the
momentum conservation equation of each micro unit in a measuring area of the particle-fluid two-phase flow reactor and acquisition of the fluid-
solid speed and the particle concentration distribution of each micro unit; S2, acquisition of matrixes which are formed by spacial discrete distribution of dilute and dense phase structural parameters; S3, acquisition of the composition concentration of dilute phase and dense phase; S4, calculation of the mean
fluid density of the micro unit according to the composition concentration of the dilute phase and the dense phase, in which, if the mean
fluid density meets the precision requirement, the fluid-
solid speed, the particle concentration and the composition concentration are outputted and the operation is ended; if the mean
fluid density fails to meet the precision requirement, the calculated mean fluid density of the dilute phase and the dense phase is substituted in the step S1, and the next iteration begins. The method introduces a multi-scale flow structure into the particle-fluid
mass transfer measuring process, takes malconformation of local
mass transfer into account, and more accurately measures the composition concentration distribution in the particle-fluid two-phase flow reactor.