Abstract: Three types of crosslinker are prepared and their properties in HPAM solution are evaluated in laboratory. To prepare organic aldehyde by sodium lactate, sodium bichromate and organic sulfur in a mess ratio of 3/1/2, and prepare composite metal crosslinker by sodium bichromate, cobalt chloride, organic sulfur and sodium lactate in 6/3/8/20. When 3 types of crosslinker are added in the HPAM solution, it is detected that the profile modification efficiency of Al-Cr composite crosslinker in HPAM polymer solution is better than that of the two others. The composite crosslinker can increase the oil recovery by 27.3% and it is suitable for applying in the formation with a temperature of about 70℃ and a salinity of 30000 mg/L.