Resource public key infrastructure (RPKI) is a key technology for enhancing border gateway protocol (BGP) security, using cryptographic verification to prevent attacks such as prefix hijacking. Since its formal deployment in 2012, RPKI has grown to cover over half of Internet prefixes. Ongoing research on RPKI deployment helps to provide insights into current trends and identify security issues. This study reviews existing works on RPKI measurement from three perspectives: RPKI data object measurement, ROV measurement, and RPKI infrastructure measurement. It analyzes RPKI data object and ROV coverage metrics, deployment trends, and the effectiveness of different measurement approaches. Moreover, key security vulnerabilities and data quality issues are identified, and recommendations to promote large-scale RPKI deployment are proposed.