A demodulation reference signal, DMRS, transmission method, comprising: determining, by a network device, a DMRS pattern for mapping data and a DMRS, corresponding to a frequency hopping mode, wherein the frequency hopping mode indicates that some symbols in one resource scheduling unit are located in a first frequency band and some other symbols are located in a second frequency band, and wherein a DMRS pattern consists of a front-loaded DMRS sequence in time domain possibly followed by an additional DMRS sequence, wherein a sequence comprises one or more consecutive symbols in time domain, different DMRS sequences are spaced apart by at least one symbol, and symbols are orthogonal frequency division multiplexed, OFDM, symbols; performing, by the network device, data and DMRS mapping by using the DMRS pattern; and sending, by the network device, a configuration parameter for additional DMRS, corresponding to the DMRS pattern to a terminal device, indicating at least one of the following: whether an additional DMRS sequence exists, a quantity of additional DMRS sequences, and a location of an additional DMRS sequence; wherein the configuration parameter for additional DMRS for determining a quantity of sequences of DMRSs in the DMRS pattern is identical for both the frequency hopping mode and a non-frequency hopping mode, and is used for determining a quantity of sequences of DMRSs in the DMRS patterns in both modes, wherein the quantity of sequences of DMRSs in the DMRS pattern in the frequency hopping mode is different from that in the non-frequency-hopping mode; sending, by the network device, the mapped data and DMRS. determining, by a network device, a DMRS pattern for mapping data and a DMRS, corresponding to a frequency hopping mode, wherein the frequency hopping mode indicates that some symbols in one resource scheduling unit are located in a first frequency band and some other symbols are located in a second frequency band, and wherein a DMRS pattern consists of a front-loaded DMRS sequence in time domain possibly followed by an additional DMRS sequence, wherein a sequence comprises one or more consecutive symbols in time domain, different DMRS sequences are spaced apart by at least one symbol, and symbols are orthogonal frequency division multiplexed, OFDM, symbols; performing, by the network device, data and DMRS mapping by using the DMRS pattern; and sending, by the network device, a configuration parameter for additional DMRS, corresponding to the DMRS pattern to a terminal device, indicating at least one of the following: whether an additional DMRS sequence exists, a quantity of additional DMRS sequences, and a location of an additional DMRS sequence; wherein the configuration parameter for additional DMRS for determining a quantity of sequences of DMRSs in the DMRS pattern is identical for both the frequency hopping mode and a non-frequency hopping mode, and is used for determining a quantity of sequences of DMRSs in the DMRS patterns in both modes, wherein the quantity of sequences of DMRSs in the DMRS pattern in the frequency hopping mode is different from that in the non-frequency-hopping mode; sending, by the network device, the mapped data and DMRS.