\documentclass[fontset=fandol,type=master,campus=harbin]{hithesisbook}
\usepackage{bm}
\begin{document}
\begin{align*}
  \min J & = -m(t_{f}) \\
  \text{s.t.} \dot{\bm{r}} & = \bm{v} \\
  \dot{\bm{r}} & = - \frac{\mu}{r^{3}}\bm{r} + \frac{\bm{T}}{m} - \frac{D}{m\lVert \bm{V}_{\mathrm{rel}}\rVert}\bm{V}_{\mathrm{rel}} \\
  \dot{\bm{m}} & = - \frac{\lVert \bm{T} \rVert}{l_{\mathrm{sp}}g_{0}}
\end{align*}
\end{document}