It is still a great challenge to explore hydrogen evolution reaction (HER) electrocatalysts with both lower overpotential and higher stability in acidic electrolytes. In this work, an efficient HER catalyst, Ru@COF‐1, is prepared by complexation of triazine‐cored sp2 carbon‐conjugated covalent organic frameworks (COFs) with ruthenium ion. Ru@COF‐1 possesses high crystallinity and porosity, which are beneficial for electrocatalysis. The large specific surface area and regular porous channels of Ru@COF‐1 facilitate full contact between reactants and catalytic sites. The nitrogen atoms of triazines are protonated in the acidic media, which greatly improve the conductivity of Ru@COF‐1. This synergistic effect makes the overpotential of Ru@COF‐1 about 200 mV at 10 mA cm–2, which is lower than other reported COFs‐based electrocatalysts. Moreover, Ru@COF‐1 exhibits exceptionally electrocatalytic durability in the acidic electrolytes. It is particularly stable and remains highly active after 1000 cyclic voltammetry cycles. Density functional theory calculations demonstrate that tetracoordinated Ru‐N2Cl2 moieties are the major contributors to the outstanding HER performance. This work provides a new idea for developing protonated HER electrocatalysts in acidic media.