To improve the current situation of excessive dust concentration in the places of mobile grinding, this thesis, based on the research background of CRCC Changke grinding workshop, establishes an unsteady single-dust diffusion model with the guidance of Gaussian diffusion model. The liner regression method is used to investigate the rules on the diffusion of multi-point dust interactions. It makes a comparative analysis of the data on the dust concentration in single point or multi points, which varies with the height. And combined with the equation for Groundwater Flow and the method of Gradient Decent, it finds out the coefficient of particle diffusion and multipoint dust interactions. The result shows that a gathering point can form between any two grinding points and it may also change with the altitude. The dust concentration of the multi-point grinding is 2 to 3 times of the single point grinding, and the maximum value is up to 45.73 mg/m3，which is higher than the standard of the state health. The average error of the dust diffusion model is verified as 14.67%, and it can be used for subsequent research on the protection technology from the dust and workshop spatial structure.