小RNA是一类长度20~24 nt、通过RNA-RNA相互作用调控目标基因的非编码RNA，其作用靶点广泛，能够多途径调节致病基因表达，已经成为新药研发热点。小RNA药物的研发依赖于RNA原料的获取，为此总结了化学合成、体外转录合成及体内生物合成3种小RNA合成方式，重点介绍了使用si-RNA结合蛋白表达siRNA、rRNA支架、tRNA支架及改良tRNA支架4种小RNA生物合成技术；提出利用杂合tRNA支架以生物发酵的方式能够大规模生产重组小RNA，该方法具有活性高、成本低、带有天然修饰、安全性高等优点，为临床RNA药物原料来源提供了备选方案。此外，归纳了美国食品药品监督管理局批准上市的14种小RNA药物以及当前在研小RNA药物的最新研究进展，分析了小RNA药物所面临的挑战及未来发展方向，以期加深对小RNA合成技术和小RNA药物研究进展的理解。

Small RNAs are a class of non-coding RNA with a length of 20~24 nt that regulate target genes through RNA-RNA interaction. Small RNAs have become a hot spot in the research and development of new drugs due to their wide range of targets and the ability to regulate the expression of pathogenic genes in multiple ways. The research and development of small RNA drugs depend on the acquisition of RNA raw materials. Based on this, three small RNA synthesis methods including chemical synthesis, in vitro transcription and in vivo biosynthesis were summarized. Four small RNA biosynthesis technologies including siRNA expressed by si-RNA-binding protein, rRNA scaffold, tRNA scaffold and modified tRNA scaffold were mainly introduced. It proposed that the use of hybrid tRNA scaffold can produce recombinant small RNA on a large scale by biological fermentation, which has the advantages of high activity, low cost, natural modification and high safety,and provides an alternative source for clinical RNA drug raw materials. In addition, 14 kinds of small RNA drugs approved by the American Food and Drug Administration (FDA) as well as the latest research progress of small RNA drugs in research were summarized. The challenges and future development directions of small RNA drugs were analyzed. This review is helpful to deepen the understanding of small RNA synthesis technology and small RNA drug research progress.