Abstract: In petrochemical production, such methods as air compressing, pump circulation, mechanical blending and pipeline mixing are usually used in product mixing. Discussed emphatically in the articleare the characteristics of the two mixing methods——pump circulation and mechanical blending. Mechanical blending is considered to be ideal through analysis and comparison. This method can make the tank liquids be mixed evenly, with the air well scattered in the liquid phase, the solid particles evenly floating so as to promote deluting, melting, scattering and reinforcing heat transfer, preventing stratified flow, settling and cleaning. There are the following advantages if this method is tried: quality product mixture, low cost, low energy combustion, simple for operation, low labor intensity, least environmental pollution. Suggestions of blender selection for multicomponent heavy oil of different viscosity are given with the advised quantily, angles and the required installation position.