调节下 scale 的参数即可。
\begin{tikzpicture}[scale=.6,mindmap, grow cyclic, sibling angle=90, every node/.style=concept, concept color=orange!40,
level 1 concept/.append style={font=\normalsize\scshape},
level 2 concept/.append style={font=\small\scshape},
level 3 concept/.append style={font=\footnotesize\scshape},
every node/.append style={align=center,scale=0.5},



问 使用 Tikz 的 mindmap 绘制思维导图如何做到自动排布各个 child?