A liquid eyeliner having a liquid storage function, comprising a container component for containing the eyeliner liquid, a coating component for drawing and applying the eyeliner liquid to the face of a user, and a cap component, wherein the coating component has a brush cover base, a brush cover, a diversion base, a connection, a diversion core, and bristles positioned and connected to one axial end of the diversion core; the brush cover base, the brush cover, the diversion base, and the connection being coaxially disposed, and all are sleeve-shaped structures that are open at both ends of the axial direction, and the rear axial end of the brush cover and the front axial end of the connection are respectively correspondingly positioned and inserted into the front and rear axial ends of the brush cover base, and the diversion base is disposed inside of the brush cover base, and located between the brush cover and the connection, and at the same time the two axial ends of the diversion base are also respectively abutted with the rear axial end of the brush cover and the front axial end of the connection; in addition, the brush cover, the diversion base, and the connection also collectively enclose a receiving cavity, the diversion core together with the bristles are all coaxial positioned and inserted into the receiving cavity, and a part of the bristles also protrudes outside the front axial end of the brush cover; also a circuit of a first convex edge extends radially outward at the outer side wall of the brush cover base; the first convex edge divides the brush cover base into a first portion corresponding to the connection, and a second portion corresponding to the brush cover, and the first portion of the brush cover base is inserted into the container component, and is in a detachable positioning connection with the container component; the cap component being detachably sleeved outside at the second portion of the brush cover base; the brush cover has a brush cover body, wherein the brush cover body is a sleeve-shaped structure that is open at both ends of the axial direction; characterized in that at least one air inlet orifice extending along the axial direction is formed at a position on the brush cover body near the front axial end, and the front side of the air inlet orifice is exposed outside the brush cover base; at least one first air exhaust groove extending along the axial direction is formed on the outer peripheral side wall of the brush cover body, and the front side of the first air exhaust groove is continuous with the air inlet orifice, and the rear side of the first air exhaust groove is continuous with a second exhaust groove on the diversion base; in addition, at least one liquid storage groove unit is further disposed on an inner circumferential side wall of the brush cover body, and each of the liquid storage groove units is respectively composed of a plurality of circular arc-shaped liquid storage grooves extending circumferentially along the brush cover body, and the several circular arc-shaped liquid storage grooves in each liquid storage groove unit are further arranged at intervals in the axial direction of the brush cover body.