Precocious puberty refers to the premature onset of pubertal development in children before a specific age threshold, which can adversely affect their growth and development, as well as their health in adulthood. Nutrition, as a key modifiable factor, is gaining increasing attention for its role in the pathogenesis of precocious puberty. This study aims to review the latest research progress on the effects of nutritional factors on precocious puberty, with a focus on the associations between early-life nutrition, childhood dietary patterns, food groups, and the intake of various nutrients with the age of sexual development. This review seeks to provide a scientific basis and strategic direction for nutritional interventions targeting precocious puberty in children.