RNA molecules are an important member of an intracellular genetic information delivery system. Conventional RNA labeling methods cannot simultaneously have the characteristics of living cells, no invasion, high temporal and spatial resolution, single molecules, etc., so a novel method for labeling and tracking RNA need to be developed. The invention discloses a novel labeling method for messengerRNA and circular RNA based on self-ligation label bimolecular fluorescence complementation. A RNA aptamer subsystem is cooperatively used, aptamers are inserted at proper positions in the RNA, and twoparts of a self-ligation label are respectively fused with the binding proteins of the RNA aptamers. When the fusion proteins do not bind to RNA, RNA molecules do not fluoresce; when and only when the fusion proteins bind to RNA, the RNA molecules fluoresce, so the fluorescence background of an intracellular RNA marker is reduced. The novel RNA labeling method based on self-ligation label bimolecular fluorescence complementation can be used for long-term interference-free single-molecule imaging observation and tracking of messenger RNA and circular RNA of living cells and fixed cells, and has good application prospects in cell biology.