In this paper, the influences of both the PNT and CNT on the THz wave generation are studied by the PIC numerical simulation. It is found that both PNT and CNT can generate THz waves with a broad bandwidth at the behind of the target. It is found that the front-end conical opening nanowire target can significantly enhance terahertz wave generation, and the terahertz wave electric field is increased by three times compared with that of the ordinary nanowire target. The reason why the CNT can enhance THz waves is analyzed in detail. The main reason is that the front-end conical opening structure of the CNT can significantly reduce the reflection of lasers, and thus improve the energy coupling efficiency between the laser and plasma. This makes a much higher cut-off energy and a larger number of hot electrons generated behind the target, which makes it radiate strong THz wave behind the target. The above results may contribute to the development of terahertz wave generation via laser-plasma interaction.