Abstract: Salinity waste water is characterised by complex pollution components, high treatment costs and difficulties, and improper treatment can cause serious ecological damage. Incineration is a harmless disposal method of salinity waste water, but because the alkali metal salts in salinity waste water may cause the ash melting temperature to decrease, resulting in corrosion of incineration equipment and accumulation of ash slag and other problems. Therefore, it is necessary to study the effects and mechanisms of common salts in saline wastewater and coal blending combustion process on the melting characteristics of coal ash. Three common salts NaCl, Na₂SO₄, and NaNO₃ from saline wastewater were loaded into two kinds of combustion coals by impregnation method and ash production was carried out at a temperature of 815°C to obtain ash samples from different coal samples. Ash melting point tests were performed for ash samples loaded with different sodium salts. It was found that under 3% sodium salt blending ratio, NaCl, Na₂SO₄ and NaNO₃ blending will significantly reduce the coal ash melting temperature, resulting in coal ash slagging. The deformation and softening temperatures of coal 1 were both highest when loaded with Na₂SO₄ and lowest when loaded with NaCl. Meanwhile, after loading the three sodium salts on Coal 1, R_z was greater than 2.5, and all of them had a tendency to severe slagging. Effect of NaCl on the ash melting temperature is particularly significant, and it will produce by-products of HCl, resulting in the corrosion of heated surfaces, and the effects of Na₂SO₄ and NaNO₃ on different coal types are slightly different. In addition, the elemental composition of the ash samples showed an increase in the total content of the alkali metal elements Na, Fe, and Ca in the ash particles as compared to that in the absence of sodium salt loading. According to the scanning electron microscopy and X-ray diffraction analysis, there was an obvious bonding phenomenon between coal 1 ash-NaCl particles and particles, and low melting point substances such as NaAlSiO₄ and KNa₃(AlSiO₄)₄ were also generated in the ash samples, and they may further form a low-temperature eutectic, which resulted in the susceptibility to slagging during the combustion process of the NaCl-loaded coal samples. Therefore, when the concentrate or crystallized salt of salt-containing wastewater and coal are mixed and burned, the mixing ratio must be strictly controlled, especially for wastewater with high NaCl content.