An information receiving and sending method and apparatus are provided, where the information receiving method includes: receiving, by a station (STA) in a transmit opportunity (TXOP) phase, orthogonal frequency division multiple access (OFDMA) data that is from a wireless access point (AP), where some data frames in the OFDMA data carry a legacy physical-layer preamble; and in a process of receiving the OFDMA data, working, by the STA, in an OFDMA receiving mode when receiving a data frame that does not carry the legacy physical-layer preamble, determining, by the STA according to a preset rule, a data frame that carries the legacy physical-layer preamble, and switching from the OFDMA receiving mode to an orthogonal frequency division multiplexing (OFDM) receiving mode to receive the data frame that carries the legacy physical-layer preamble.