The invention discloses a closed-loop feedback phase-lock-type laser frequency sweep system. The closed-loop feedback phase-lock-type laser frequency sweep system comprises a main system; the main system comprises a scanning unit module, a signal processing module, a current controller, an LD module, and a first coupler which are successively connected in series; the closed-loop feedback phase-lock-type laser frequency sweep system further comprises a feedback system; the feedback system comprises a second coupler, an optical path system module, an optical path detector, and a phase modulator which are successively connected in series; and the second coupler is connected with the first coupler, and the signal output end of the system is leaded out from the connection place of the second coupler and the first coupler. The phase modulator is used for sending the obtained reference signal and the transmission feedback signal passing through a photoelectric detector to a signal processing module together, and sending the data of the scanning unit module and the data of the signal processing module to the current controller together, and the current controller combines the obtained data and the data on a temperature controller and the data passes through the first coupler together, the signal is finally outputted from the signal output end of the system.