Sodium spray fire could happen in sodium-cooled fast reactor, which will cause the rapid rise of temperature and pressure in the vessel. In this paper, based on the droplet pre-combustion model, droplet motion model, multi-node spray fire combustion model and flow field model, a one-dimensional sodium fire combustion analysis code NAFCALX is developed. Its original droplet group combustion model and other inadequacies are improved, coupling the change of droplet with the movement of droplet during droplet combustion. The improved model is used to simulate the ABCOVE and KAERI sodium spray fire experiments. The predicted temperature and pressure peaks and the trend of temperature changing with time were in good agreement with the experimental values, which is much better than that from the original model. Through the comparison and analysis of the calculation results, the accuracy of the improved model is verified.