A physical protocol data unit (PPDU) transmission method includes: setting parameters of each of a plurality of links for enabling the plurality of links to have different capacity for PPDU transmission, wherein parameters of one link are different from parameters of another link, and highest capacity supported by the one link is higher than highest capacity supported by the another link; aligning an ending time instant of transmission of a first PPDU transmitted via the one link with an ending time instant of transmission of a second PPDU transmitted via the another link through setting a content that is carried by the first PPDU transmitted via the one link; and transmitting PPDUs via the plurality of links, wherein one PPDU is transmitted via each of the plurality of links, and the PPDUs include the first PPDU and the second PPDU.