Objective To systematically evaluate the health hazards of dibutyl phthalate （DBP） using the weight of evidence approach， identify its key toxicological effects and evidence strength， and provide scientific basis for risk management.Methods Literature in Chinese and English databases was retrieved from the earliest available records of DBP-related research up to September 20， 2024. The reliability and relevance of experimental and epidemiological studies were assessed in accordance with the toxicological data evaluation guidelines developed by the China National Center for Food Safety Risk Assessment. Based on the weight of evidence， the evidence streams for experimental and population studies were established， and comprehensive evidence integration was conducted from multiple dimensions including consistency， association strength， and biological plausibility. Meta-analysis was performed for homogeneous epidemiological studies.Results A total of 423 experimental studies and 62 eligible epidemiological studies were included. Weight of evidence integration indicated that sufficient evidence supported the reproductive and developmental toxicity of DBP， with a critical lowest observed adverse effect level （LOAEL） at 2 mg/（kg?BW?d）. Epidemiological evidence revealed that DBP exposure significantly increased the risk of preterm birth in humans （pooled OR=1.10， 95% CI： 1.01-1.20）. Evidence for immunotoxicity was limited yet critical， where animal studies demonstrated adverse immunological effects induced at a dose of 0.4 mg/（kg?BW?d）， which was lower than the LOAEL for reproductive toxicity. Limited evidence was obtained for neurotoxicity and metabolic toxicity， while evidence regarding cardiovascular toxicity and genotoxicity was insufficient. No significant correlation was identified between DBP exposure and male sperm quality via meta-analysis.Conclusion Systematic assessment based on the weight of evidence approach confirms that reproductive and developmental toxicity represents the key effect endpoints with the strongest evidence for DBP currently. Existing toxicological data supports the maintaining of its tolerable daily intake at 0.01 mg/（kg?BW）. Meanwhile， immunotoxicity is recognized as a potentially sensitive endpoint requiring high priority attention. The weight of evidence integration framework demonstrated in this study provides a methodological reference for comprehensive hazard assessments of DBP and other chemicals.