The invention discloses a plastic straight-head high-voltage connector, which comprises a plug assembly and a socket assembly, wherein the plug assembly comprises a tail cover, a cable waterproof ring, shielding rings, jack sleeves, a position guaranteeing part, a plug shell, a head waterproof ring, a plug shielding cover, a plug rubber core and signal pins; and the socket assembly comprises a socket shell, a signal jack piece, a socket waterproof ring and a socket shielding cover. As the position guaranteeing part is arranged reasonably, accurate abut joint between the plug assembly and the socket assembly can be ensured, and the connection effects are good; through match between a positioning slot and an external sleeve part and match between a connector and an internal sleeve part, thecoupling is tighter, falling is not easy, and the match stability is enhanced; the shielding effects are good, external interference is reduced, the sealing effects are good, the possibility of entering of water and dust is thus reduced, the working reliability is effectively ensured, the service life is long, and besides, a man hand can be prevented from touching the jack sleeve or the connectionpin due to error operation, the use safety is greatly improved, and wide promotion and application are facilitated.