The invention discloses a fully-sealed capacitor which comprises an aluminum cylinder with one open end. An electrolyte layer is arranged inside the cylinder, a sealing layer for sealing the cylinder is arranged at the open end of the cylinder, an anode pin penetrates into the sealing layer to be communicated with the electrolyte layer, and a cathode pin is arranged on the outer side of the sealing layer and communicated with the cylinder. The electrolyte layer comprises a plurality of pieces of electrolyte paper and conductive paper, and the electrolyte paper and the conductive paper are alternately arranged around the axial line of the cylinder. The fully-sealed capacitor is reasonable in structural design, the conductivity of the fully-sealed capacitor is enhanced through alternate arrangement of the electrolyte paper and the conductive paper, the sealing performance of the fully-sealed capacitor is enhanced through arrangement of a concave groove and a convex edge, and a good sealing effect helps prolong the service life of the capacitor.