更新：

Question

以下 MWE 根据节级别生成具有不同对齐方式的 ToC。如何强制所有节级别左对齐？

梅威瑟：

\documentclass[12pt]{report}
%-> For bibliography
\usepackage[num, overcite]{abntex2cite}

%-> Generate dummy text
\usepackage{lipsum}

%-> Change section numbering style
\renewcommand{\thesection}{\arabic{section}}

%-> Add References to ToC
% \usepackage[nottoc, section]{tocbibind}

\usepackage{etoolbox}

\usepackage[hang]{footmisc}

\begin{document}
\tableofcontents

\newpage
\section{Section one}
\subsection{Section one, subsection one}
\lipsum[1]

And here, in this paragraph, I need to cite someone~\cite{ClrT10ca}. This reference will appear in the bibliography area below. And here I will add a footnote%
    \footnote{This is the desired footnote}
because I want to see how it is displayed.

\subsection{Section one, subsection two}
\lipsum[2]

\section{Section two}
\lipsum[3]


\addcontentsline{toc}{section}{\protect\numberline{}\bibname}
\bibliographystyle{abntex2-num}
\bibliography{bib}
\end{document}

围兜文件：

@article{ClrT10ca,
    author = {Tracey M. Clarke and James R. Durrant},
    title = {Charge Photogeneration in Organic Solar Cells},
    journal = {Chemical Reviews},
    volume = {110},
    number = {11},
    pages = {6736-6767},
    year = {2010}    }

更新：

注意：这个abntex2cite包裹对于我的工作至关重要，任何其他包裹都无法替代。

Answer 1

有了这个包就可以了tocloft。

\usepackage{tocloft}
\setlength{\cftpartindent}{0em}
\setlength{\cftchapindent}{0em}
\setlength{\cftsecindent}{0em}
\setlength{\cftsubsecindent}{0em}
\setlength{\cftsubsubsecindent}{0em}
% etc

请参阅手册（> texdoc tocloft）以了解详细信息。

Answer 2

这是一个解决方案titletoc：

\documentclass[12pt]{report}
\usepackage[showframe]{geometry}
%-> For bibliography
%\RequirePackage[num, overcite]{abntex2cite}

\usepackage{lipsum}

%-> Change section numbering style
\renewcommand{\thesection}{\arabic{section}}

%-> Add References to ToC
% \RequirePackage[nottoc, section]{tocbibind}

\usepackage{etoolbox}
% \apptocmd{\thebibliography}{\csname phantomsection\endcsname\addcontentsline{toc}{chapter}{\bibname}}{}{}

\usepackage[hang]{footmisc}

\usepackage{titletoc}
  \titlecontents{subsection}
 [1.5em] %
 {\smallskip}
 {\thecontentslabel\hspace{1.02em}}%\thecontentslabel
{\hspace*{2.32em}}
 {\,\,\titlerule*[0.77pc]{.}\contentspage}

\begin{document}

\tableofcontents

\newpage
\section{Section one}
\subsection{Section one, subsection one}
\lipsum[1]

And here, in this paragraph, I need to cite someone~\cite{ClrT10ca}. This reference will appear in the bibliography area below. And here I will add a footnote%
    \footnote{This is the desired footnote}
because I want to see how it is displayed.

\subsection{Section one, subsection two}
\lipsum[2]

\subsection*{An unnumbered subsection}
\addcontentsline{toc}{subsection}{An unnumbered subsection}

\section{Section two}
\lipsum[3]

\addcontentsline{toc}{section}{\protect\numberline{}\bibname}
\bibliographystyle{abntex2-num}
\bibliography{bib}

\end{document}