With the rapid development of the Internet of Things (IoT), the number of various smart devices has increased sharply, and identity authentication has become the primary requirement for ensuring the security and credibility of IoT. Blockchain, as a distributed ledger technology, provides a trusted collaboration environment and a secure data management platform. The use of blockchain technology to drive IoT authentication has become a hot spot in academia and industry. This article analyzes the main requirements of authentication mechanism design based on cloud computing and cloud-edge collaboration. The challenges in applying blockchain technology to IoT scenarios are pointed out. The works on IoT authentication mechanisms are collected and classified into three categories:key-based authentication, certificate-based authentication, and identity-based authentication. Moreover, the existing IoT authentication works using blockchain technology are analyzed comparatively. The relevant documents are categorized and discussed according to authentication objects and additional attributes. We summarize the security analysis method for the blockchain-based IoT authentication mechanism from both formal and informal perspectives. Finally, we look into the future of the field.