Cloud ERP system realizes the functions of ERP in the way of cloud service, which greatly improves the service level of ERP and reduces the cost for enterprise to use ERP. Cloud ERP system has the characteristics of open ecology, therefore the interactions between users increase, which brings data security risks to the cloud ERP platform. This paper discusses the security of cloud ERP system from the perspective of ecosystem, and puts forward the concept and connotation of cloud ERP ecosystem. The LDA method is used to analyze the literature related to the security of ecosystem and cloud ERP open ecology, based on which seven main themes are summarized. It mainly focuses on system risk assessment, information security management and platform ecosystem construction. Based on LDA analysis results, this paper constructs a cloud ERP ecosystem security evaluation system using expert interviews from three dimensions: developer ecosystem security, user ecosystem security and device-system-user ecosystem security.