The invention relates to the technical field of variable-section extrusion molding of aluminum alloy seamless pipes, in particular to an extrusion process of a variable-section aluminum alloy drilling rod. The extrusion process comprises the following steps: (A) according to the weight percentage requirements of aluminum alloy raw material components, the aluminum alloy raw materials are molten to manufacture an aluminum rod; (B) the surface of the molten aluminum rod is removed; and the aluminum rod is heated for homogenization, and is cooled to reach the room temperature; (C) the homogenized aluminum rod is preheated; meanwhile, an extrusion cylinder, an extrusion mold and an extrusion needle of a variable-section drilling rod extrusion device are preheated; the extrusion mold is taken out to assemble in an extruder; and the aluminum rod is taken out to fill in the extrusion cylinder of the extrusion mold for extrusion molding; and (D) the extruded aluminum alloy is heated to manufacture the variable-section aluminum alloy drilling rod. The extrusion process changes the extrusion molding conditions through optimizing the aluminum alloy components, so that the variable-section aluminum alloy drilling rod is easy to mold; and the needed mechanical performance is achieved through heat treatment.