The invention discloses a fault identification method and system for a multivariable industrial process. The fault identification method comprises the steps of receiving a normal operating condition data set and fault mode data sets and carrying out standardized processing the fault mode data sets to obtain normalized fault mode data sets according to the normal operating condition data set; obtaining statistic mode matrixes of various fault mode data sets by adopting a moving window technique; detecting a transmission fault in the industrial process, receiving a to-be-identified data set formed by real-time fault data and obtaining a normalized to-be-identified data set according to the normal operating condition data set; obtaining the statistic mode matrix of the to-be-identified data set by adopting the moving window technique; extracting fault directions from the statistic mode matrixes of various fault mode data sets in a statistic mode space, carrying out fault reconstruction on the statistic mode matrixes of to-be-identified data along the fault directions of various fault mode data in a residual space in sequence; and calculating fault identification indexes and determining fault types of the to-be-identified fault data.