The quality of highways is crucial to the national economy and people's lives. The quality evaluation system for highway engineering has developed rapidly in recent years, but the data security and authenticity of the quality evaluation system cannot be guaranteed. With the popularization of big data and cloud computing, more and more data are stored and processed in cloud environments. Traditional privacy protection and secure sharing methods are no longer sufficient to meet the large-scale and complex nature of data. How to protect private data and achieve secure data sharing has become an urgent problem to be solved. Therefore, combining blockchain technology and data security sharing, we propose a multiuser data security sharing system in a cloud environment, which ensures the security of highway engineering system data while improving the efficiency of user query and storage of data.