Christensen insightfully proposed disruptive innovation. The theory is growing stronger but is still haunted by vagueness and post hoc definition issues, which signifies the nature of disruptive innovation may remain unveiled. In order to eliminate the controversies and confusion, this study sorts out commonalities and key driving forces for market encroachment of disruptive innovation, and utilizes the interpretative structural model to reorganize the original theoretical framework based on the principle of “Occam’s razor”. The results show that (1) the value network is the theoretical outset of disruptive innovation and manifests as two different value dimensions at the product or technical level, which endows disruptive innovation with “duality”; (2) the duality makes disruptive innovation have asymmetric advantages and disadvantages compared to existing products or technologies in terms of price and performance; The asymmetry changes enterprises’ competition basis and consumers’ evaluation matrices, which essentially explains the key to market encroachment of disruptive innovation; (3) the duality is the essence that distinguishes disruptive innovation from other types of innovation.