he ballastless track of highspeed railways should be of good stability, continuity and high evenness. High accuracy threedimensional control survey technology is needed in the construction of the ballastless track. Taking the survey practice in Feiluan Tunnel on WenzhouFuzhou Railway and Jiuniushan Tunnel and Fenghuangshan Tunnel on NingboTaizhouWenzhou Railway as example, the author presents the characteristics, technical requirements and survey method of CPIII control points survey technology for the ballastless track of highspeed railways and makes analysis on some survey errors.