Based on the theory of technology trajectory, this paper, by taking how smartphone technology subverts the traditional mobile phone technology as an example, analyzes the JΛL curve of the amount of patents, patent citation and patent citation rate over time by patents’ citation information, which is crawled down by applying the Python programming in Derwent Innovation Index database. The result reveals the smartphone’s technology evolution trajectory, establishes the analysis framework of disruptive technology evolution and proposes the patent impact factor to realize the early identification of disruptive technology, hoping to provide researchers with useful information.