The embodiments of the present application relate to the technical field of wireless communications, and in particular, to a method, system and device for transmitting feedback information, used for realizing simultaneous feedback of multi-carrier ACK/NACK and periodical CSI. The method for sending feedback information in the embodiments of the present application includes: user equipment determining a PUCCH resource corresponding to first feedback information in second feedback information periodical reporting subframes; the user equipment determining feedback information to be transmitted and including the first feedback information according to the determined PUCCH resource and transmitting same via the PUCCH resource corresponding to the first feedback information. Since the user equipment determines feedback information including first feedback information according to the PUCCH resource corresponding to the first feedback information in the second feedback information periodical reporting subframes and transmits same via the determined PUCCH resource, thus realizing simultaneous feedback of multi-carrier ACK/NACK and periodical CSI.