Fatty acid ester defoamers are environmentally friendly antifoaming agents utilizing ester compounds synthesized from natural fatty acids and polyols through esterification reactions as core components. Their molecular structure combines hydrophilic groups with hydrophobic long chains, which disrupt the oriented arrangement at foam interfaces to reduce local surface tension, promoting liquid drainage and film thinning until rupture occurs. These defoamers demonstrate excellent biodegradability and environmental compatibility, maintaining stability across wide pH ranges without causing contamination or surface defects in subsequent processes. Particularly suitable for environmentally sensitive applications including food processing, bio-fermentation, textile dyeing, and wastewater treatment, their superior dispersibility and persistent foam suppression make them ideal alternatives to conventional defoamers. Certain specific fatty acid esters additionally provide lubricating functions, enhancing system fluidity while performing defoaming actions.