Aiming at the time-optimal control problem of hypersonic vehicles （HSV） in ascending stage， a trigonometric regularization method （TRM） is introduced based on the indirect method of optimal control. This method avoids analyzing the switching function and distinguishing between singular control and bang-bang control， where the singular control problem is more complicated. While in bang-bang control， the costate variables are unsmooth due to the control jumping， resulting in difficulty in solving the two-point boundary value problem （TPBVP） induced by the indirect method. Aiming at the easy divergence when solving the TPBVP， the continuation method is introduced. This method uses the solution of the simplified problem as the initial value of the iteration. Then through solving a series of TPBVP， it approximates to the solution of the original complex problem. The calculation results show that through the above two methods， the time-optimal control problem of HSV in ascending stage under the complex model can be solved conveniently.