Abstract: Disclosed is a railway vehicle major component and system diagnosis apparatus, which includes: a railway vehicle state summarizer that generates a feature value for at least one major component and system of a railway vehicle by summarizing sensing values collected through a plurality of sensors for a first period as a multi-dimensional railway vehicle parameter; a database generator that generates a database for at least one major component and system of a railway vehicle by normally distributing a plurality of feature values accumulated for a second period composed of a plurality of continuous first periods; and a railway vehicle diagnosis performer that detects and precisely diagnose abnormal situations in at least one major component and system of a railway vehicle on the basis of the database for major components and systems.