The invention provides a drug crystal library based on a block chain and a construction method thereof, and the drug crystal library comprises that a first layer is a crystal source data layer and isused for acquiring crystal information and storing drug crystal original data, and the security and privacy are guaranteed by a data holder; the second layer is a crystal representation layer, is usedfor crystal information chaining, stores crystal information documents generated according to corresponding standards, and ensures unique identification of one crystal form; and the third layer is acrystal index layer, is used for querying crystal related information, is realized through blockchain nodes, and stores shared document index information and query information. The method is suitablefor construction of a drug molecular crystal library, drug molecular crystal form information is managed by using a block chain, functions of adding, searching, comparing and the like of drug molecular crystal forms are realized in combination with software, and the purposes of protecting, authorizing and the like of the molecular crystal forms are achieved.