Objective Based on the cloud platform of ancient and modern medical records, this paper studies the rules of traditional Chinese medicine clinical prescription decoction pieces in Longnan First People′s Hospital, and provide reference for the medication specification requirements for compiling the prescription of traditional Chinese medicine decoction pieces in Longnan First People′s Hospital. Methods The prescriptions of clinical decoction pieces of traditional Chinese medicine in Longnan First People′s Hospital from January 2020 to January 2021 were collected. The hospital information system (HIS) was used for statistical inquiry, sorting out, screening and standardized processing,the database of traditional Chinese medicine clinical prescription decoction pieces in Longnan First People′s Hospital was established, the frequency analysis, dosage interval analysis of decoction pieces, and dosage point analysis of decoction pieces were performed using the cloud platform of ancient and modern medical records, and the medication rules such as four natures, five flavors, channel tropism and efficacy of traditional Chinese medicine clinical prescription decoction pieces in Longnan First People′s Hospital were analyzed. Results A total of 17 749 traditional chinese medicine clinical prescriptions were included, involving 360 herbs, and the top 100 herbs with the highest frequency of use were statistically analyzed, Codonopsis pilosula, Angelica sinensis, and Roasted Radix Glycyrrhizae were the most frequently used herbs, and warm, flat, and slightly cold were the most frequent natures, the sweet, pungent, and bitter were the most frequent flavors, the herbs mostly entered the lung, spleen, and liver channels, and the clinical dosage were most concentrated at 5, 6, 10, 12, and 15 g. Conclusion Through data mining, it is found that the prescription drugs of traditional Chinese medicine decoction pieces in Longnan First People′s Hospital have strong regional characteristics, and there are some differences with the dosage of Pharmacopoeia, but the overall attributes and dosage rules have certain clinical value.