This paper summarized the research methods of variant book text of

Important Formulas Worth a Thousand Gold Pieces for Emergency

（《备急千金要方》） by analyzing the revised medical books of Song Dynasty， which mainly included mutual reference and proof between literature and history， cultural and scientific mutual proof to distinguish the false and retain the true， text research of variant book versions to comprehend by analogy. Influenced by the philosophical social thought， and the dominance of revision work by Confucianism， the the revising method used in the Song Dynasty has changed the basic composition of original books， resulting in the complexity and uncertainty of content in the handed down revised medical books of Song Dynasty. For the variant book texts containing the core medical elements， especially the formula dosage， in the medical books of the Song Dynasty should be interpreted with the aid of multiple discipline knowledge such as philology， traditional linguistics， traditional Chinese medicine， so as to make reasonable judgement， offer reliable interpretation， and make full use of the literature， and then provide reference for the theoretical research and clinical application of traditional Chinese medicine.