An optical amplifier assembly capable of dynamically performing optical time-domain reflection detection, comprising a first band Raman pump, a second band Raman pump, a circulator, a first optical wavelength division multiplexer, a second optical wavelength division multiplex, a signal light splitter, a first photodetector, a second photodetector, a third photodetector and a processor, wherein: the signal light splitter is connected in series in a signal optical path, and its optical splitting port is connected to an input port of the first optical wavelength division multiplexer, and two output ports of the first optical wavelength division multiplexer are connected to the first photodetector and the second photo detector, respectively, lights from the first band Raman pump, the second band Raman pump and the signal optical path are multiplexed into a transmission fiber through the second optical wavelength division multiplexer, wherein the first band Raman pump is one of a C-band Raman pump and an L-band Raman pump, and the second band is the other of the C-band Raman pump and the L-band Raman pump, an output port of the first band Raman pump is connected to a first input end of the circulator, a first output port and a second output port of the circulator are respectively connected to a second input port of the second optical wavelength division multiplexer and the third photodetector, a third input port of the second optical wavelength division multiplexer is connected to the second band Raman pump, an output port of the second optical wavelength division multiplexer is used for connection with a transmission fiber, and a first input port of the second optical wavelength division multiplexer is connected with a signal optical path; the circulator is disposed downstream of the first band Raman pump to provide a portion of the light from the first band Raman pump to the third photodetector, data communication ports of the first band Raman pump, the second band Raman pump, the first photodetector, the second photodetector and the third photodetector are connected to the processor, the first band Raman pump has two operating modes comprising a Raman optical fiber amplifier operating mode and an optical time-domain reflection detection mode, and the processor operates to obtain signal light intensity detection signals from the first photodetector and the second photodetector, and to send a control signal to the first band Raman pump when it is determined that the signal light intensity in the second photodetector is lower than a first present threshold, so that the first band Raman pump enters into the optical time-domain reflection detection mode, wherein the first band Raman pump is used as an OTDR detection light source. the signal light splitter is connected in series in a signal optical path, and its optical splitting port is connected to an input port of the first optical wavelength division multiplexer, and two output ports of the first optical wavelength division multiplexer are connected to the first photodetector and the second photo detector, respectively, lights from the first band Raman pump, the second band Raman pump and the signal optical path are multiplexed into a transmission fiber through the second optical wavelength division multiplexer, wherein the first band Raman pump is one of a C-band Raman pump and an L-band Raman pump, and the second band is the other of the C-band Raman pump and the L-band Raman pump, an output port of the first band Raman pump is connected to a first input end of the circulator, a first output port and a second output port of the circulator are respectively connected to a second input port of the second optical wavelength division multiplexer and the third photodetector, a third input port of the second optical wavelength division multiplexer is connected to the second band Raman pump, an output port of the second optical wavelength division multiplexer is used for connection with a transmission fiber, and a first input port of the second optical wavelength division multiplexer is connected with a signal optical path; the circulator is disposed downstream of the first band Raman pump to provide a portion of the light from the first band Raman pump to the third photodetector, data communication ports of the first band Raman pump, the second band Raman pump, the first photodetector, the second photodetector and the third photodetector are connected to the processor, the first band Raman pump has two operating modes comprising a Raman optical fiber amplifier operating mode and an optical time-domain reflection detection mode, and the processor operates to obtain signal light intensity detection signals from the first photodetector and the second photodetector, and to send a control signal to the first band Raman pump when it is determined that the signal light intensity in the second photodetector is lower than a first present threshold, so that the first band Raman pump enters into the optical time-domain reflection detection mode, wherein the first band Raman pump is used as an OTDR detection light source.