In response to the need for detecting column concentrations of greenhouse gases in the marine atmosphere， a 1.57 µm near-infrared laser heterodyne radiometric detection system suitable for shipborne platforms was developed. An image tracking algorithm was developed based on a low-cost surveillance pan-tilt system. The algorithm delay was reduced by simplifying the image processing and control algorithms. This enabled stable solar tracking on a shipborne dynamic platform. A measurement method with local oscillator laser temperature step tuning was proposed. This reduces the impact of tracking errors and non-short noise， thereby improving the signal-to-noise ratio of the measurements. Sea trials were conducted in the South China Sea using the system， and the maximum measured tracking error was 1.98 mrad， meeting the requirements for laser heterodyne detection. Continuous monitoring of atmospheric CO₂ column concentration was achieved during both cruising and drifting modes. The fluctuation in the measured CO₂ column concentration was less than ±1.0×10^-6， reducing the fluctuation range to 1/12 of that observed with traditional local oscillator laser current tuning. This system provides the technical means for subsequent detection of background greenhouse gas column concentrations in the marine atmosphere.