The invention discloses a space dust distribution rule analyzing method of an underground grain channel, and belongs to the technical field of dust distribution rule analyzing inside the grain channel. The technical purpose is to solve the problem that a dust prevention system inside the grain channel cannot be scientifically deployed and controlled since the dust distribution rule inside the underground grain channel cannot be effectively analyzed. The method comprises the steps of firstly, constructing a structure model of the underground grain channel, and selecting dust monitoring sites inthe structure model; conducting analog simulation on the dust flowing situation of the underground grain channel; putting up a test platform, and obtaining original monitoring data of the dust monitoring sites through a senor arranged on the test platform; adopting an Euler-lagrange algorithm to calculate the original monitoring data to obtain fluid flow transporting equations of a continuous phase and particle distribution data of a discrete phase; building a k-allele model according to the fluid flow transporting equations and the particle distribution data of the discrete phase, and calculating grain dust change distribution rule data relevant to temperature and humidity data. The space dust distribution rule analyzing method of the underground grain channel is used for analyzing the dust distribution rule.