In conference mode you already have the \IEEEauthorblockN for (N)ame and \IEEEauthorblockA for (A)ffilition of each author in the column format. You then introduce line breaks in the same cell to put the second ones. The columns are seperated by \and commands.
\documentclass[conference]{IEEEtran}
\usepackage{lipsum} %<---- For dummy text
\title{Some IEEE paper}
\author{
\IEEEauthorblockN{Michael Shell}
\IEEEauthorblockA{School of Electrical and\\
Computer Engineering\\
Georgia Institute of Technology\\
Atlanta, Georgia 30332--0250\\
Email: mshell@ece.gatech.edu}\\ %<------ Line breaks in the current column
\IEEEauthorblockN{Michael Shell}
\IEEEauthorblockA{School of Electrical and\\
Computer Engineering\\
Georgia Institute of Technology\\
Atlanta, Georgia 30332--0250\\
Email: mshell@ece.gatech.edu}
\and
\IEEEauthorblockN{Homer Simpson}
\IEEEauthorblockA{Twentieth Century Fox\\
Springfield, USA\\
Email: homer@thesimpsons.com}\\[0.9cm] %<------- Extra vertical space
\IEEEauthorblockN{Homer Simpson}
\IEEEauthorblockA{Twentieth Century Fox\\
Springfield, USA\\
Email: homer@thesimpsons.com}
\and
\IEEEauthorblockN{James Kirk\\
and Montgomery Scott}
\IEEEauthorblockA{Starfleet Academy\\
San Francisco, California 96678-2391\\
Telephone: (800) 555--1212\\
Fax: (888) 555--1212}\\ %<-----------
\IEEEauthorblockN{James Kirk\\
and Montgomery Scott}
\IEEEauthorblockA{Starfleet Academy\\
San Francisco, California 96678-2391\\
Telephone: (800) 555--1212\\
Fax: (888) 555--1212}
}
\begin{document}
\maketitle
\begin{abstract}
\lipsum[1]
\end{abstract}
\lipsum[2-6]
\end{document}
