As the trusted decentralized application, smart contracts attract widespread attention, whereas their security vulnerabilities threaten the reliability. To this end, researchers employ various advanced technologies (such as fuzz testing, machine learning, and formal verification) to study several vulnerability detection technologies and yield sound effects. This study collects 84 related papers by July 2021 to systematically sort out and analyze existing vulnerability detection technologies of smart contracts. First of all, vulnerability detection technologies are categorized according to their core methodologies. These technologies are analyzed from the aspects of implementation methods, vulnerability categories, and experimental data. Additionally, the differences between domestic and international research in these aspects are compared. Finally, after summarizing the existing technologies, the study discusses the challenges of vulnerability detection technologies and potential research directions.