I use biblatex to create the formatted bibliography, and I want to order citations in an alphabetical order of auther's name and then publicated year by ascending. I post a picture to show what I want:

As we can see from above, the style is like plain,which is what I want.However, the order of references is not in an alphabetical order of auther.
I found several methods on the forum but none of them satisfy my needs.
I tried this, but it fails:
\documentclass{article}
\usepackage[sorting=ydnt]{biblatex}
\addbibresource{\ref.bib}
\begin{document}
\nocite{*}
\printbibliography
\end{document}

ydnt= years descending -> name -> title). – moewe Jan 13 '20 at 17:30sorring=ydnt,and what result you did in fact obtain. There is also a possibly discrepancy between the title, which talks about the bib sorting order and the body of the questions, which mentions citation sorting order. Usually I would interpret citation sorting order as the order of citations in multi-cites like\cite{sigfridsson,worman}. – moewe Jan 15 '20 at 20:14biblatex, and find a useful guide of using it on overleaf! This guide solves my question!@moewe – Travis Jan 16 '20 at 03:30