A data sending method, comprising: determining, by a base station, a time-domain interval of available time-frequency resources in an unlicensed spectrum, wherein the available time-frequency resources are continuous time-frequency resources in a time domain, wherein the unlicensed spectrum is anchored to a licensed primary carrier and has the same timing relationship as the primary carrier, with LTE frames being divided into subframes with same numbers and boundaries; and sending, by the base station, in an initial first subframe that comprises the beginning of the interval, a preamble signal, downlink control information and data, wherein the preamble signal is a predefined sequence, so as to allow user equipment to perform detection on the preamble signal according to the predefined sequence, and a specific mapping relationship exists between the preamble sequence and the unlicensed spectrum, wherein the location of the downlink control information is a location in the unlicensed spectrum according to the preamble signal, wherein the downlink control information comprises scheduling indication information, location indication information, duration indication information, and data symbol indication information, the scheduling indication information is used to indicate a frequency-domain location of the data, the location indication information is used to indicate a time domain location of the data, and the duration indication information is used to indicate available duration of the base station in the unlicensed spectrum, wherein the data symbol indication information is used to indicate an end location of the data in a third subframe that is a last subframe in the time-domain interval of available time-frequency resources in the unlicensed spectrum. determining, by a base station, a time-domain interval of available time-frequency resources in an unlicensed spectrum, wherein the available time-frequency resources are continuous time-frequency resources in a time domain, wherein the unlicensed spectrum is anchored to a licensed primary carrier and has the same timing relationship as the primary carrier, with LTE frames being divided into subframes with same numbers and boundaries; and sending, by the base station, in an initial first subframe that comprises the beginning of the interval, a preamble signal, downlink control information and data, wherein the preamble signal is a predefined sequence, so as to allow user equipment to perform detection on the preamble signal according to the predefined sequence, and a specific mapping relationship exists between the preamble sequence and the unlicensed spectrum, wherein the location of the downlink control information is a location in the unlicensed spectrum according to the preamble signal, wherein the downlink control information comprises scheduling indication information, location indication information, duration indication information, and data symbol indication information, the scheduling indication information is used to indicate a frequency-domain location of the data, the location indication information is used to indicate a time domain location of the data, and the duration indication information is used to indicate available duration of the base station in the unlicensed spectrum, wherein the data symbol indication information is used to indicate an end location of the data in a third subframe that is a last subframe in the time-domain interval of available time-frequency resources in the unlicensed spectrum.