The invention discloses a polyethylene geomembrane special welding rod and a making technique thereof; the polyethylene geomembrane special welding rod is made of basic resin, master batch, antioxygen and light stabilizer by the making technique which comprises following steps: raw materials blending, melt extrusion, die head forming, circulating water cooling for shaping, on-line detection by optoelectronic equipment, rolling up, blanking, finished product inspection and finished product warehousing; the invention adopts domestic raw materials to replace imported raw materials and provides an unique formulation; meanwhile, by adopting advanced making technique, the invention has the advantages of novel technological route, low equipment investment, simple processing procedure, short processing period, no dust and environmental pollution, high raw material utilization rate, low energy consumption, good product performance, stable quality and low manufacturing cost, and can produce the high-performance and high-quality geomembrane special welding rod which is in line with engineering requirements and can substitute imported products.