This review explores the intricate interactions between entomopathogenic fungi (EPF) and insects across three key infection stages: early infection, penetration and intra-hemolymph growth, and host insect death. In the early infection stage, insects employ various strategies to detect and avoid EPF, including behavioral responses and the use of ectomicrobiomes. The insects' cuticle serves as a protective barrier, but EPF can adhere to and penetrate this barrier through hydrophobins and appressoria formation. During the penetration and intra-hemolymph growth phase, EPF initiate cellular and humoral immune responses in insects, while symbiotic microbes further enhance host resistance. In the final stage, infected insects isolate themselves from the healthy population, while EPF secrete antimicrobial products to limit the growth of competing microbes. The review also discusses a novel pest management strategy that involves modifying EPF to enhance virulence and disrupting insect immune systems, providing new perspectives for effective fungal insecticides.This review explores the intricate interactions between entomopathogenic fungi (EPF) and insects across three key infection stages: early infection, penetration and intra-hemolymph growth, and host insect death. In the early infection stage, insects employ various strategies to detect and avoid EPF, including behavioral responses and the use of ectomicrobiomes. The insects' cuticle serves as a protective barrier, but EPF can adhere to and penetrate this barrier through hydrophobins and appressoria formation. During the penetration and intra-hemolymph growth phase, EPF initiate cellular and humoral immune responses in insects, while symbiotic microbes further enhance host resistance. In the final stage, infected insects isolate themselves from the healthy population, while EPF secrete antimicrobial products to limit the growth of competing microbes. The review also discusses a novel pest management strategy that involves modifying EPF to enhance virulence and disrupting insect immune systems, providing new perspectives for effective fungal insecticides.