The embodiment of the invention provides a combiner, a Doherty amplifier and a base station applying the Doherty amplifier. The combiner comprises a first quarter-wave line, a second quarter-wave line, a third quarter-wave line, a fourth quarter-wave line and a system load resistor, wherein one end of the first quarter-wave line is connected with the output terminal of a main power amplifying branch circuit and the second quarter-wave line, the other end of the first quarter-wave line is connected with the system load resistor and the fourth quarter-wave line; and one end of the third quarter-wave line is connected with the output terminal of an auxiliary power amplifying branch circuit and the second quarter-wave line, and the other end of the third quarter-wave line is connected with thefourth quarter-wave line. Therefore, application of the Doherty amplifier in a broadband is realized, and working efficiency of a radio frequency power amplifier is effectively improved.