The embodiments of the present invention provide a feedback information transmission method and a terminal device, which relate to the field of communications technologies and are used to resolve the problem of how a terminal device sends feedback information in a multi-TRP communications system. The method is applied to a terminal device and includes: in the case of receiving at least two PDCCHs sent by at least two TRPs or different antenna panels of one TRP, determining a target PUCCH resource, and sending target feedback information through the target PUCCH resource, where the target feedback information is feedback information of each PDSCH scheduled by the at least two PDCCHs. The embodiments of the present invention are used for the transmission of feedback information.