The invention discloses a co-axial type radial thrust rod high speed indexing mechanism, comprising a box body, an input shaft and an output shaft. The axial lines of the input shaft and the output shaft are on a same line; the end part of the input shaft is fixed with a driving cirque which is provided with at least a pair of symmetrical radial through holes; the output shaft is fixedly connected with at least a pair of symmetrical cranks; the end part of the crank is respectively provided with at least one first roller; the box body is fixed with an internal profile conjugate cam; each pair of symmetrical through holes on the driving cirque are internally provided with a thrust rod respectively; one end of the thrust rod is provided with a second roller which is contacted with the internal profile conjugate cam; the other end of the thrust rod is in flat bottom structure which is contacted with the first roller at the end part of the crank. The indexing mechanism of the invention can be widely applied to automatic machines with large indexing number range, compact structure, large rigidity, high bearing force, coaxial input and output and high speed indexing intermittent motion, such as various machines of printing, packaging, foods, ceramics, pharmacy, military industries, etc.