For studying airflow field distribution rules on vibrating screener’s surface,the airflow running through the up sieve surface were measured. Results indicate that the airflow is stable along horizontal direction,and the sequence of wind speed of each lines, from the largest to the smallest in size, is fifth row, third row, second row and fourth row along the longitudinal direction. By using 1stOpt software, to fit the wind speed values, and the wind speed distribution equation of up sieve surface under different fan speeds was obtained. Using Matlab software to convert the equation to the surface diagram, indicated that the airflow distribution tends to rise at first, slightly decline at middle part, and rise again at the end in general, and the fan rotation speed of fan mainly affect the size of the airflow velocity of up sieve and almost has no effect on the distribution of airflow field of the entire.