The invention discloses a swept source based on a multi-rotating mirror and with an adjustable initial wavelength and duty cycle and relates to the swept source optical coherence tomography technology. The swept source is characterized in that a signal generator 6 outputs a first signal and a second signal which are identical in period and different in duty cycle, a tunable filter drive module 7 is connected with the first signal and used for driving the multi-rotating mirror 10 in a tunable filter 3, and a current control module 5 is connected with the second signal and used for modulating the injection current waveform of a semiconductor optical amplifier 1. The swept source has the advantages that the time delay between the current control module 5 and the tunable filter drive module 7can be regulated by regulating the initial time delay, compared with the second signal, of the first signal, and accordingly, the initial wavelength of the output spectrum of the swept source can be changed; the injection current waveform of the semiconductor optical amplifier 1 is regulated by changing the first signal input to the current control module 5, and accordingly the spectrum output range of the semiconductor optical amplifier 1 is controlled, and the duty cycle of the swept source can be regulated finally.