\documentclass[12pt, a4paper]{book} \usepackage[no-files]{xsim} \usepackage{ctex} \usepackage{amsmath,amssymb} \usepackage{amsthm} \usepackage{enumerate} \usepackage{xeCJK} \xsimsetup{ exercise/within = section , exercise/the-counter = \thesection.\arabic{exercise} } \begin{document} \part{试题} \chapter{第一章} \section{第一节} \begin{exercise} 111T \end{exercise} \begin{solution} 111D \end{solution}

\begin{exercise} 222T \end{exercise} \begin{solution} 222D \end{solution} \section{第二节} \begin{exercise} I'm an excercise2. \end{exercise} \begin{solution} I'm a solution2. \end{solution} \chapter{第二章} \section{第一节} \begin{exercise} 11111T \end{exercise} \begin{solution} 11111D \end{solution} \section{第二节} \begin{exercise} 22222222222T \end{exercise} \begin{solution} 222222222222D \end{solution}

\setcounter{chapter}{0} \setcounter{section}{0} \part{答案} \chapter{第一章} \section{第一节} \printsolutions[chapter=1,section=1] \section{第二节} \printsolutions[chapter=1,section=2] \chapter{第二章} \section{第一节} \printsolutions[chapter=2,section=1] \section{第二节} \printsolutions[chapter=2,section=2] \end{document}