Blockchain technology is the integration and innovation of multiple technologies and it has also become a hot spot with the attention from various aspects. Due to the complexity of the technologies involved, the threshold of blockchain technology has been relatively high, which is not conducive to the spread and popularity of blockchain technology. This paper summarizes of the structure, consensus mechanism, certificate mechanism, P2P protocol and other technologies involved in the blockchain according to the mainstream open source blockchain projects, and analyzes the features of blockchain from a technical perspective. Besides,it aims to clarify the characteristics of blockchain technology, the logic of blockchain techno logy, and promote the practical of blockchain technology. The conclusion of this paper have reference value for the in-depth study of blockchain practitioners and blockchain technology.