The effects of weak-alkali ASP composition on the o/w emulsion-stabilizing properties of simulative produced liquid by the weak-alkali ASP flooding were analyzed by use of spinning-drop interfacial-tension (IFT) meters, microscopes, zeta-potential analyzer and Turbiscan laboratory expert stabilizer in this work. The experimental results showed that the irregular movement of the droplets in the lower and middle regions is the main cause of the instability of the emulsion system. The addition of alkali changes the movement of emulsion droplets formed by the weak-alkali ASP system and the oil. Both weak-alkali and surfactants play dual roles in the ASP system. The optimum amount can make the emulsion achieve the best stability and less or more amounts are not conducive to the stability of the emulsion. Appropriately increasing the polymer concentration is helpful to increase the stability of the emulsion. However, the addition of an excessively high concentration of polymer does not increase the stability of the emulsion, resulting in unnecessary waste. It is expected that this study will be of guiding significance for the mechanism of weak-alkali ASP flooding and the treatment of produced liquid in actual production.