Abstract: Regarding the problems that appeared in the engineering research and innovation, it advances the ways of describing and analyzing contradictions, based on the extenics, presents some concepts of contradiction degree, contradiction function and transformation function, and constructs a model for engineering contradiction. At the same time, according to the important idea that solving the main contradiction is the key to innovation in the engineering research, it proposes the identification algorithm for the main contradiction—normal partition algorithm, which is an effective technical method for intelligent processing of contradiction by the computer.

Key words: contradiction element; contradiction function; main contradiction; extension model