Abstract: Innovation leap mean the variability of firm's innovation behavior along the temporal dimension, representing the recognition of technological trajectories, exploration of technological opportunities in the future, and getting rid of the routine of technological development. On account of not enough attention paid to the antecedents of innovation leap in existing literature, this paper investigates the knowledge-base antecedents of innovation leap from the perspective of ambidextrous transition and technological knowledge system. Using the panel data of 489 enterprises in strategic emerging industries in China, this paper find: (1) the diversification of technological knowledge system has positive effects on innovation leap, and related diversification has greater effect than unrelated diversification;（2）the uniqueness of technological knowledge system and innovation leap shows inverted U-shaped relationship. This paper extending the studies of the antecedents of innovation leap and provides some implications for firms to construct suitable technological knowledge to explore the technological opportunities in the future.