Abstract: Due to the problems that acidizing working fluid has high corrosion ratio, small acidification radius and no effect on organic scale by using conventional acidification technology during the injection of low permeability and low-pressure reservoir, a new multifunctional activated acidizing working fluid was developed. Through optimization and compound of the acid system treatment agent, multifunctional activated acid system formula was obtained: SZJ 20%+SFJ 6.7%+HCl 10%+ZRJ 2.5%+scale-dissolving agent 5.0%+water. The acid system has a good retarded effect, dissolution capacity, and good solubilization capability for organic scale in formation at 45 ℃, moreover, it has excellent corrosion inhibition and anti-swelling capacity. The corrosion rate is less than 2.5 mg/(m²·h) and the anti-swelling rate of the working system before and after acidification is larger than 90% and 85%, respectively.