Transition-metal-catalyzed C–H activation represents one of most attractive research fields in modern organic chemistry while theoretical studies have become a popular and effective tool for elucidating mechanism nowadays. The recent achievements in the cross field of the two orientations are reviewed in this article. The first part introduced the advances in theoretical study on transition-metal-catalyzed C–H activation. The elegant work reported mainly in and after 2013, classified according to the mechanisms of C–H activation, were covered. The second part provided an analysis on the distribution of quantum-chemical methods, solvation models and basis sets in the collected theoretical studies. Transition-metal-catalyzed C-H activation represented one of the most attractive research fields in modern organic chemistry while theoretical studies have become a popular and effective tool for elucidating mechanism nowadays. The recent achievements in the cross field of the two orientations are reviewed in this article. The first part introduced the advances in theoretical study on transition-metal-catalyzed C-H activation. The elegant work reported mainly in and after 2013, classified according to the mechanisms of C-H activation, were covered. The second part provided an analysis on the distribution of quantum-chemical methods, solvation models and basis sets in the collected theoretical studies.