We propose a class of nodal line semimetals that host an eightfold-degenerate double Dirac (DDNL) with negligible spin-orbit coupling. find only 5 the 230 space groups DDNL. The DDNL can be considered as combination two lines, and has trivial Berry phase. This leads to possible but completely different surface states, namely, torus state covering whole Brillouin zone no at all. Based on first-p...