Provided are a preamble symbol receiving method and a receiving device, characterized in that: the received preamble symbol contains a time-domain symbol which is generated from a single three-segment structure by a transmitting end according to a predefined generation rule, the single three-segment structure containing: a time-domain main body signal, a prefix generated based on the entirety or a portion of the time-domain main body signal, and a postfix or a hyper prefix generated based on the entirety or a portion of the time-domain main body signal. Therefore, using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to implement coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels.