Abstract: The present invention belongs to the field of medicinal chemistry, and particularly relates to a pleuromutilin derivative with a thiazole side chain and preparation and application. The pleuromutilin derivative with the thiazole side chain is a compound of formula 2 or a pharmaceutically acceptable salt thereof, and a solvent compound, enantiomer, diastereoisomer, tautomer, or mixture of any proportion of the compound of formula 2 or the pharmaceutically acceptable salt thereof, comprising racemic mixtures: The pleuromutilin derivative has good antibacterial activity, is particularly suitable for use as a novel antibacterial drug for animal or human systemic infection, and has good water solubility.