The invention discloses an extrusion forming agent, and preparation and use thereof, in particular to a forming agent for a tungsten-based alloy or hard alloy or ceramic powder extrusion forming process, and preparation and use thereof. The forming agent comprises 60 to 80 percent of solid and liquid paraffin wax, 3 to 8 percent of carnauba wax, 10 to 20 percent of high density polyethylene and ethylene-vinylacetate copolymer, 1 to 8 percent of plasticizer, 1 to 5 percent of stearic acid and the balance of modifier. In the invention, the drawbacks of long degreasing time, low degreasing conformality and more degreasing defects of extrusion blanks, particularly large-size extrusion blanks, are overcome, the raw materials are cheap and easy to purchase, the component compatibility of the prepared forming agent is high, the forming agent is used in a powder extrusion forming process, the micro structure of the forming agent is uniform, the forming agent has strong interaction force with powder, the formability is high, the quick and flawless degreasing of blanks with a thickness of 40 millimeters can be realize, the production efficiency is improved, and the development of extrusion forming industry is promoted greatly.