This paper investigates the problem of classifying and predicting fitness zones for underwater gravity-aided navigation. Firstly, a refined baseline map is generated by interpolating and filling in missing data. Based on the methods of repetitive simulation and machine learning, we compare the machine learning KNN, SVM, PSO-BP neural network with the integrated learning XGBoost, RF, MARS and other models, and finally determine to establish the classification prediction system of SVM. Secondly, the idea of area micronutrient is applied to transform the points into rectangular area micronutrients. Through K-means clustering calculation, the calibration of the fitness area is completed, including excellent, good, average, and poor fitness area. A starting point is established based on the area microelement, and this point is geometrically processed with its 8 neighboring orientation points to produce 9 new regional characteristic attribute indicators. The most representative and critical 12 regional characteristic attribute indicators are finally determined. The AUCs of SVM, RF, and XGBoost with hyperparameter optimization of the data were 0.97, 0.90, and 0.91, and then, considering the simplicity and robustness of the processing problem, the underwater fitness zone classification prediction system based on SVM was finally established, and the prediction of the model migratory was carried out.