The invention discloses a low overshoot voltage unidirectional TVS, which comprises a P-type substrate and an N+ concentrated phosphorus region diffused on the upper and lower surfaces of the P-type substrate, and the N+ concentrated phosphorus region covers the upper and lower surface areas of the P-type substrate respectively. 2 / 3-5 / 6; the upper surface of the TVS device is oxidized with a silicon dioxide passivation layer, the upper surface of the TVS device is provided with a metal electrode K, and the lower surface of the TVS device is provided with a metal electrode A; the invention also discloses the low A method for manufacturing an overshoot voltage unidirectional TVS, comprising the following steps: step S1, substrate preparation; step S2, oxidation; step S3, photolithography of the concentrated phosphorus region; step S4, diffusion of the concentrated phosphorus region; step S5, photolithography of the lead hole ; Step S6, steaming aluminum; Step S7, aluminum reverse etching; Step S8, steaming aluminum alloy; Step S9, steaming Ti-Ni-Ag alloy; Step S10, Ti-Ni-Ag reverse etching. Compared with the unidirectional TVS of the traditional structure, the present invention has one more concentrated phosphorus diffusion region and one less boron concentration diffusion region in structure, and diffuses the concentrated phosphorus region on the lower surface of the P-type substrate, which can effectively reduce the overshoot voltage and enhance the device. surge capability.