The present invention discloses a method and an apparatus for adjusting a data transmission rate, where the method includes: acquiring information for resource scheduling that is determined by a base station according to information about resource quantity, where the information about resource quantity indicates a quantity of resources that can be scheduled by the base station; receiving first frequency domain data transmitted at a first transmission rate; according to information for resource scheduling, buffering first frequency domain data borne by an occupied data bearer unit, and discarding first frequency domain data borne by an idle data bearer unit; and transmitting, at a second transmission rate, the buffered first frequency domain data, where the second transmission rate is lower than the first transmission rate. According to the method and the apparatus for adjusting a data transmission rate, by buffering the first frequency domain data borne by the occupied data bearer unit, and by discarding the first frequency domain data borne by the idle data bearer unit, the data transmission rate can be adjusted while a service is kept running, so as to adapt to different data transmission conditions, thereby being able to improve system transmission performance.