Summary: Nowadays, energy development has been plagued by such problems as the difficulty of controlling energy development and ensuring the balance of supply and demand, the serious overcapacity, and the redundancy of energy resource circulation. Blockchain technology is highly compatible with such field because of its features including decentralization, openness, independence, security, anonymity, etc. The current studies on "blockchain+energy" are focused on the application and remain insufficient on the current situation of cooperation between various subjects, with most research featuring qualitative analysis. This article employs Vosviewer for bibliometric analysis and then, from both qualitative and quantitative perspectives, provides a systematic literature review in the field of "blockchain+energy" via scientific cartography. Meanwhile, this review is diversified for also analyzing ample aspects, such as policies and regulations, national cooperation, institutional cooperation, author cooperation, research hotspots, research differences, application progress, development trend, etc. Based on the research results, policy recommendations are proposed in terms of external environment and internal technology, including one that the external environment should focus on policy support and talent cultivation, and the internal technology should focus on blockchain core technology development and security control. In this way, this article aims to provide reference for the future blockchain research, application model innovation, and relevant policy makers. [ABSTRACT FROM AUTHOR]