Aiming at the disadvantages of traditional titration detection methods such as low sensitivity, poor anti-interference ability, and long detection period, this paper uses liquid chromatography tandem quadrupole mass spectrometer to establish a detection method for α-olefin sulfonates used in oil and gas fields, and realizes the detection of target concentration in olefin sulfonate products, injection fluid and produced fluid. The detection conditions are as follows: the chromatographic column is an anionic column; the mobile phase is 55% methanol + 45% 8 mmol/L ammonium acetate aqueous solution (volume ratio), isocratic Elution; mass spectrometry detection conditions are electrospray ion source, negative mode, full scan. The recovery rates of this method for olefin sulfonate products, injection fluid, and produced fluid were 82.63-96.37%, 78.60-95.41%, 82.68-95.72%, respectively. One sample detection was completed in 8 minutes, and the lower limit of quantification was 5 ppm. And polymer, trace oil, etc. have no effect on the detection result, that is, the method is fast, sensitive, and has strong anti-interference ability.