Steam dryness detection is crucial in the field of oil exploitation. Steam dryness too high will be dangerous, whereas steam dryness too low will affect the efficiency of extraction. Therefore, real-time, high-precision detection of steam dryness is essential. The methods for detecting steam dryness include chemical, thermodynamic, radiometric, and microwave. The manual test method possesses the best detection accuracy. However, the real-time performance is not good, and the detection process is cumbersome. Here we propose using a silver nitrate solution to titrate chloride ions and combining them with the change in the absorbance of the solution to determine the endpoint of the titration. We report that the automatic chloride ion concentration measurement was a rep and that the detection of chloride ion concentration was 15 mg/L. The detection linearity reached 0.992. Therefore, our titration endpoint judgment method has better anti-interference.