Embodiments of the present invention provide a data transmission method and an apparatus. In the method, a communications node receives N spatial reuse parameters SRPs; the communications node determines, based on the received N SRPs, that the communications node can perform spatial reuse link transmission; and the communications node transmits data by using a spatial reuse link, and processes data transmission based on the spatial reuse link. Whether spatial reuse link transmission can be performed is determined based on the received SRPs, so as to reduce mutual interference between a primary link and the spatial reuse link during data transmission, and improve transmission quality.