Accurate and reliable forestry data can be obtained by means of continuous monitoring of forests using advanced technologies, which provides a major opportunity for the development of smart forestry. However, with the improvement of the precision and acquisition speed of data, the traditional data analysis, and storage technology cannot meet the performance requirements of current applications. Forestry big data has brought a new solution to the difficulties encountered in the course of forestry development, which refers to the application of big data technology to forestry data processing. In this paper, we summarize the research and work of the big data in smart forestry in recent years. First, we review the history of the emergence and development of forestry big data, and then briefly summarize the opportunities brought to the forestry by big data technology. One of the most important tasks of forestry big data is to organize the massive data reasonably and effectively and to calculate fast. Therefore, we propose a five-layer architecture model of forestry big data and summarize the related work of data storage, query, analysis, and application. Finally, the challenges of forestry big data are analyzed, and the trend of future development has prospected from three aspects.