【Objective】The composting and return of food waste to the soil are of great significance to the sustainable development of urban food systems. However, it is still unclear how the salt in this composted food remains affects the soil in the long run. Thus, this study aimed to investigate the risk of soil salinization caused by salt (NaCl) carried by food waste composted using different methods. 【Method】A four-season field observation experiment was conducted in vegetable plots. A total of five treatments were established: nitrogen-free control (CK), conventional chemical fertilizer (CF), conventional chicken manure + chemical fertilizer (MF), food waste aerobic compost + chemical fertilizer (FWAF), food waste digestate + chemical fertilizer (FWDF). Vegetable yield, soil electrical conductivity (EC) at a depth of 0-20 cm, sodium (Na+) and chloride (Cl-) concentrations, soil sodium adsorption ratio (SAR), plant uptake of Na+ and Cl-, and the annual input-output balance of soil Na+ and Cl- were measured. 【Result】The results showed: (1) Under conditions of 20% nitrogen reduction, both methods of food waste composting increased vegetable yields compared with CF and MF treatments, with the FWDF treatment showing a significant increase. (2) Compared with the CF and MF treatments, food waste composting had no significant effect on soil electrical conductivity (EC), and none of the treated soils reached the level of salinization. (3) The SAR values for the FWAF and FWDF treatments were significantly lower than those for the CF treatment, but there was no significant difference compared with the MF treatment. Also, the SAR values for all treatments were below the risk threshold (<13). (4) In the top 0-20 cm soil layer, the Na+ content in the FWAF treatment was 25.5% higher than in the CF treatment, but there was no significant difference compared with the MF treatment. However, the Cl- content in the FWAF and FWDF treatments was significantly higher than in the CF treatment, but there was no significant difference compared with the MF treatment. (5) The Na+ and Cl- balance indicates that shallow irrigation water in the study area is the primary source of soil Na+ and Cl-, accounting for 51%-73% and 63%-85% of total Na+ and Cl- inputs, respectively, which is significantly higher than the contribution from aerobic food waste compost (Na+ 29%, Cl- 14%) and anaerobic food waste digestate (Na+ 11%, Cl- 2%). 【Conclusion】In coastal regions, the NaCl introduced into the soil through the application of compost from aerobic kitchen waste and anaerobic digester sludge is not a major factor in soil salinization. In the south-eastern coastal and southern regions of China, where rainfall causes intense leaching, the risk of residual Na+ and Cl- in soil resulting from the composting of both types of food waste remains at a manageable level compared to the use of traditional organic fertilizer (chicken manure). These regions are therefore priority areas for the application of food waste compost to farmland.