A preferably kind of chemical decompression and augmented injection system was studied under the temperature of 50 centigrade in this paper. The basic recipe was obtained as follows: 0.05% dimeric surfactant HA-1, 0.1% ethanol amine MEA and 0.1% methanol, which could decline instantaneous minimum interfacial tension (IFT_min) between oil and water to 3.78×10^-5 mN/m. The system’s performance on changing wettability, resistance to inorganic salts and temperature was investigated. The results showed that the system could convert the oil-wet surface to wet surface observably, and the contact angle between simulated formation water and core decreased from 130° to 60° after 33 hrs. When the dosage of NaCl was 5000—20000 mg/L, IFT_min could reach 10^-2—10^-5mN/m. While when 50—200 mg/L CaCl₂ was added, IFT_min and equilibrium interfacial tension would reach 10^-3 and 10^-2 mN/m orders of magnitude, respectively. The system was suitable for the reservoir with the conditions of 5000—20000 mg/L NaCl, less than 200 mg/L CaCl₂, and 40~70℃. The core displacement experiment results showed that the depressurization rate of the system could reach to 20%, and the system had a good decompression and augmented injection effect for low permeability reservoir.