AbstractIn regions characterised by high humidity and abundant vegetation, the external insulation materials utilised in high‐voltage transmission and transformation are frequently fouled with a multitude of microorganisms, thereby jeopardising the reliable operation of the power grid. A comprehensive overview of the periodic growth regulation of parasitic algae is presented upon insulating composites across various regions of the world. Additionally, it highlights the methods for quantitative evaluation and accurate prediction of algae coverage degree. Also, the biological contaminates coating process and the artificial flashover test method are summarised, and the effects of algae on the reliability of inorganic and organic materials used for external insulation are compared. It emphasises the dynamic hygroscopic characteristics and cytoelectronegativity of cell secretions as the critical factors that negatively affect the hydrophobicity and flashover performance of silicone rubber insulators by algae. Furthermore, valuable insights into the long‐term inhibition of algae growth on polymeric insulators are provided using eco‐friendly antibiotic‐loaded silica aerogel nanocomposites.