The result of a technical economics research on core drilling methods is described in this article.This research aims at introducing the idea of technical economics in drilling technical design,to realize the optimization of core drilling method selection.The formula for calculation of drilling time has been deduced.Through calculation and comparison,several core drilling methods that are being widely used or just being improved in China,have been evaluated.The evaluation result shows that hydro-hammer drilling method is a high efficiency drilling method that is worthwhile to be popularized widely.