Jigger is the main equipment in coal processing industry in China, which is developed towards large-scale device. By using the homemade device LTX-35 jigger as a model employing mesh division with non-orthogonal mesh for different kinds of through-flow passage, and completing the numerical simulation with the computational fluid dynamics (CDF) software-PHOENICS, the velocity distribution in different flow fields resulting from guide plates of varied structures are obtained. The results from the simulation show that 1 ) the degree of velocity uniformity of the flow field can be improved if a flat guide plate is replaced by a curved one in the jigger; 2) the best result can be achieved by using a semicircular guide plate.