将`&`换成& ``` \documentclass{article} \usepackage{amsmath,mathtools} \begin{document} \begin{align*} D_{\alpha \beta \gamma}=\left[\begin{array}{lll} D_{11} & D_{12} & D_{13} \\ D_{21} & D_{22} & D_{23} \\ D_{31} & D_{32} & D_{33} \end{array}\right] &= \left[\begin{array}{l} \cos \beta \cos \gamma \\ \cos \beta \sin \gamma \\ -\sin \beta \end{array}\right.\\ &\mathrel{\phantom{=}} \left.\begin{array}{ll} -\cos \alpha \sin \gamma+\sin \alpha \sin \beta \cos \gamma & \sin \alpha \sin \gamma+\cos \alpha \sin \beta \cos \gamma \\ \cos \alpha \cos \gamma+\sin \alpha \sin \beta \sin \gamma & -\sin \alpha \cos \gamma+\cos \alpha \sin \beta \sin \gamma \\ \sin \alpha \cos \beta & \cos \alpha \cos \beta \end{array}\right] \end{align*} \begin{align*} D_{\alpha \beta \gamma}&=\left[\begin{array}{lll} D_{11} & D_{12} & D_{13} \\ D_{21} & D_{22} & D_{23} \\ D_{31} & D_{32} & D_{33} \end{array}\right] \\ &=\begin{bsmallmatrix} \cos \beta \cos \gamma & -\cos \alpha \sin \gamma+\sin \alpha \sin \beta \cos \gamma & \sin \alpha \sin \gamma+\cos \alpha \sin \beta \cos \gamma \\ \cos \beta \sin \gamma & \cos \alpha \cos \gamma+\sin \alpha \sin \beta \sin \gamma & -\sin \alpha \cos \gamma+\cos \alpha \sin \beta \sin \gamma \\ -\sin \beta & \sin \alpha \cos \beta & \cos \alpha \cos \beta \end{bsmallmatrix} \end{align*} \end{document} ```