Interdisciplinary thematic projects implemented by means of the electronic library "Scientific heritage of Russia" allow integrating objects of various nature (printed publications, archival documents, multimedia objects) into a single thematic resource and making it accessible to users. The approaches to the formation of interdisciplinary thematic collections in the digital space of scientific knowledge are investigated. Algorithms for the formation and presentation of a digital interdisciplinary collection are presented. The method of creation and presentation of virtual collections in the information environment of the electronic library "Scientific heritage of Russia". The main types of sections present in most projects are indicated. The main stages of the formation of an interdisciplinary collection in the digital space of knowledge have been formed and described, including the composition of the collection sections, sources for presenting collection materials, dispatching work with sources, the formation of metadata, the main types of sections, etc. An example of the application of the content formation methodology for creating an interdisciplinary collection is given.