The utility model discloses a dual -use storage tank, this storage tank including the apron and the box, the box is equipped with the bracket with the surface that the apron lid closed, has placed the sealing washer on the bracket, the range all around of box lateral wall is followed to the sealing washer, has seted up the caulking groove on the sealing washer, and the apron lower surface is equipped with and covers the interior sealed fin of fashionable insertible caulking groove, the box constitutes by plastics with the apron. The surface of closing at box and apron lid is equipped with the bracket, places the sealing washer in the bracket, and the sealing washer sets up along box a week, makes the sealed lid of box and apron close, makes the article of putting in the box mould proof of can preventing damp, having seted up the caulking groove again on the sealing washer, in the sealed fin of messenger's setting on the apron lower surface embeds the caulking groove, having prevented that the apron is fashionable at the lid, the not tight condition is sealed in the appearance, use foaming polyvinyl chloride to make box and apron, can prevent damp, the mould proof, not absorb water, effectively prolong the life of storage tank.