To determine the optimal concentration of NaCl for identifying salt tolerance in maize seedlings, 16 representative inbred lines were selected. These lines were treated with NaCl concentrations of 0, 100, 150, 200, 250, and 300 mmol/L for 7 days. Six indicators, including shoot height, root length, shoot and root fresh weight, and shoot and root dry weight, were measured and the seedling conditions were recorded. The results indicated that the appropriate range was between 150-200 mmol/L of NaCl, with variations in the indicators greater than 200 mmol/L except for root length at 150 mmol/L NaCl treatment. Based on these findings, a salt tolerance identification system was established for maize seedlings, which involved evaluating multiple indicators under the optimal NaCl concentration. Using this system, 76 maize inbred lines were analyzed. A comprehensive salt tolerance evaluation index (D) was calculated using the weighted subordinate function method, and the lines were clustered into four groups: high salt tolerance, salt tolerance, salt sensitivity, and high salt susceptibility. Among these, Ming71, Zhong106, Si-287, and 8112 showed the highest salt tolerance, making them valuable resources for breeding salt tolerance in maize. The correlation between the salt tolerance coefficient of shoot fresh weight and the D value was found to be the strongest, suggesting that it can be used as the primary indicator for evaluating salt tolerance in maize inbred lines during the seedling stage.