This paper presents a vulnerability detection scheme for small unmanned aerial vehicle (UAV) systems, aiming to enhance their security resilience. It initiates with a comprehensive analysis of UAV system composition, operational principles, and the multifaceted security threats they face, ranging from software vulnerabilities in flight control systems to hardware weaknesses, communication link insecurities, and ground station management vulnerabilities. Subsequently, an automated vulnerability detection framework is designed, comprising three tiers: information gathering, interaction analysis, and report presentation, integrated with fuzz testing techniques for thorough examination of UAV control systems. Experimental outcomes validate the efficacy of the proposed scheme by revealing weak password issues in the target UAV s services and its susceptibility to abnormal inputs. The study not only confirms the practical utility of the approach but also contributes valuable insights and methodologies to UAV security, paving the way for future advancements in AI-integrated smart gray-box fuzz testing technologies.