The present disclosure relates to a method and an apparatus for sending and receiving a downlink data block of a packet data service. A network side adds indication information of downlink data modulation modes to a downlink data block, where the downlink data block includes first information and second information; the network performs symbol mapping processing on the first information by using a first modulation mode to obtain a first modulated signal; the network performs symbol mapping processing and data pre-processing on the second information by using a second modulation mode to obtain a second modulated signal; the network combines these two modulated signals to obtain an aggregate modulated signal; and the network sends the aggregate modulated signal. With the present disclosure, throughput of downlink data is increased while a USF compatibility between more types of low-capability mobile terminals is considered.