We　report　a　continuous-wave　terahertz　computed　tomography　using　Bessel　beam　generated　by　the　axicon.　Two-dimensional　cross-sectional　images　of　the　internal　structure　of　plastic　pipes　at　different　distances　are　reconstructed　by　using　the　filtered　back　projection　algorithm.　Compared　with　conventional　Gaussian　beam,　Bessel　beam　can　extend　the　depth　of　field　and　improve　the　fidelity　of　the　reconstruction.