The invention discloses an automatic placing method and an automatic placing device for a protective sheet before storage battery capping. The device comprises a rack, which is provided with a strip cutting mechanism connected with a complete protective sheet and used for cutting the protective sheet into strips, and a sheet cutting mechanism connected with the strip-shaped protective sheet and used for cutting the protective sheet into sheets with required lengths, wherein the sheet cutting mechanism is provided with a supporting plate, the supporting plate is provided with a channel for allowing the sheet-shaped protective sheets to pass through, the opening of the channel inclines towards the side lower portion, and a sheet cutting knife is arranged above the edge of the channel; or a middle plate is arranged at the opening of the channel, a through hole is formed in the middle plate from top to bottom, the protective sheet extends to the position above the through hole, and a sheetcutting knife is arranged above the position, close to the side surface of the channel, of the through hole. According to the invention, a protective sheet is divided into a plurality of strips fromone end of the protective sheet through the automatic placing device, the strips are pulled to to-be-placed holes, and the protective sheets meeting the length requirement are spit out through the automatic placing device and cut off, so that the protective sheets can accurately, rapidly and efficiently fall into the placing holes from top to bottom.