Crossborder M&A has become the necessary means for Chinese commercial banks to survive and develop, and M&A performance is an important criterion to measure whether a M&A case is successful. Based on threestage DEA, by using BootstrapDEA to correct the deviations, not only the environmental factors and random factors on the performance can be eliminated but also the accuracy of the performance can be further improved, which is the effective choice to get efficient solution of performance. Through the adoption of the threestage DEA after modified by Bootstrap model to make empirical analysis of the performance of crossborder M&A of China’s commercial banks and to examine the overall situation of their M&A, the research finds that the performance values solved by threestage DEA model after Bootstrap modification are more accurate, among which, the M&A year, pure technical performance, scale efficiency, and technical efficiency were respectively rising to some extent and have been declining to different extents in the later several years.