Dibenzyl-toluene was synthesized and characterized using GC,IR,TG and NMR methods.The physicochemical properties of dibenzyl-toluene and its thermal stability experiment for 1000 h were also investigated.Results showed that the properties of lab-made dibenzyl-toluene can well meet the requirement of GB 23971-2009.The L-QD 340 product has been obtained when the thermal stability experiment was completed at 340 ℃.