The invention discloses a characterization method for powder macroscopic flow during an extrusion molding process. The method comprises the following steps of: extrusion analog machine preparation, wherein an extruding nozzle and a piston are mounted at a lower section and an upper section of a material barrel, and a powder raw material chamber is disposed between the extruding nozzle and the piston; powder raw material preparation, wherein main powder is spread on the bottom of the powder chamber chamber, auxiliary powder is added, the two kinds of powder are added repeatedly for several times, the weight of the main powder at each layer is the same, and the weight of the auxiliary powder at each layer is the same; extrusion billet body preparation, wherein a certain amount of powder in the material barrel is extruded by a pressing device, and residual materials are enough for powder flow rule characterization; pressed billet removal from the material barrel; pressed billet dissection, wherein flow state curves of the main powder and the auxiliary powder can be observed at its profile, which represent the macroscopic flow characteristics of the main powder. The method of the invention characterizes a movement track and flow characteristics of powder in an extrusion material cylinder during an extrusion process by a trace method, and provides basis for research of problems of protrusion of a rod billet edge compared with a rod billet core, easy cracks of extruded profiled bars, radial cracks after large-size pressed billet drying, and the like.