Embodiments provide a signal transmission method and apparatus. The method includes: modulating, by using a phase-shift keying PSK scheme with rotation of a first angle, at least a part of pilot information carried in at least one signaling symbol in a signaling field of a data packet, to obtain modulated pilot information; and sending, to a receive end, a data packet that carries the modulated pilot information. A modulation scheme different from a conventional modulation scheme is used in the embodiments to modulate pilot information carried in a signaling symbol in a signaling field of a data packet, so that a data packet format corresponding to the modulation scheme can be effectively detected at a receive end.