Although the widespread application of big data has promoted the development of the network industry，it also poses serious threats to personal information security. In the era of big data，personal information faces three major dilemmas：personal information processing and protection，information flow and security，and rights transfer and protection. These dilemmas are mainly based on multiple social roots，such as the impact of big data technology on the existing personal information protection system，the indifferent concept of personal information protection，and the practical needs of social governance. In this regard，there is an urgent need to reconstruct the concept of rights，strengthen technical specifications，and build a network co-regulation system to break through the predicament and comprehensively improve personal information security.