In the boilers of thermal power plants, traditional steels and their alloys cannot resist corrosion at high temperatures. The efficiency of the thermal power plant is seriously threatened by high-temperature corrosion of coal-fired boiler elements. Preserving these surfaces against material loss is crucial, since it could result in higher repair and maintenance cost. To overcome this, many corrosion control techniques are commonly employed. However, a deep and flawless coating applied using the thermal spray approach has demonstrated encouraging results in the fight against hot corrosion. The current work reviews the function of thermal spray coatings in coal-fired power plants to safeguard various steel grades subjected to high temperatures and deteriorating condition. Many researchers have recently attempted to use surface coatings to reduce hot corrosion of boiler steels. Thus this paper discussed the unique method of thermal spray coatings.