The invention relates to intermolecular Cr 3+ cross-linked polymer gel and a production process. The intermolecular Cr 3+ cross-linked polymer gel comprises the following components which are matched according to mass concentration, wherein partial hydrolysis polyacrylamide is used as host crystal whose concentration range is 0.04%-0.12 %, organic chromium is used as cross linking agent in which the mass concentration of Cr 3+ is calculated based on the mass concentration of polymer, wherein polymer: Cr 3+ = 40:1-100:1, and oil-field produced water or source water is used as solvent. The polymer gel has the characteristics of low viscosity, rapid gel forming speed, large flow resistance and controllable flow ability, which can be used to adjust water injection profile of a water injectionwell in oil fields which are driven by water, and simultaneously expresses excellent technology and economy.