A polarization processing optical device, wherein the optical device comprises a polarization beam splitter, PBS, a polarization rotator, PR, a first coupler, a first phase tuner, PT, a photodetector, PD, a second coupler, a second PT, a radio frequency electrode, and a driver, wherein the PBS comprises three ports, one of the three ports of the PBS is configured to input a continuous light source, the other two of the three ports of the PBS are respectively connected to one port of the PR and a first port of the first coupler, and the PR is configured to perform polarization rotation on an optical energy output by the PBS; the other port of the PR is connected to one port of the first PT, the other port of the first PT is connected to a second port of the first coupler; or the other two of the three ports of the PBS are respectively connected to one port of the PR and one port of the first PT, and the PR is configured to perform polarization rotation on an optical energy output by the PBS; the other port of the PR is connected to a second port of the first coupler, the other port of the first PT is connected to a first port of the first coupler; a third port and a fourth port of the first coupler are configured to output single-polarization light in a same polarization state; wherein the second PT is placed between the third port of the first coupler and the second coupler, or between the fourth port of the first coupler and the second coupler, and the second PT is configured to control a phase of light passing through the second PT, so that there is a preset proportion of optical power output by the second coupler to peak power; the PD is placed between the third port of the first coupler and the second coupler, or between the fourth port of the first coupler and the second coupler, wherein the first PT is configured to control output optical power of the third port and the fourth port to be equal based on the obtained optical power information output by the PD; the radio frequency electrode is placed between the third port of the first coupler and the second coupler, or between the fourth port of the first coupler and the second coupler; the driver is configured to drive the radio frequency electrode; and the second coupler comprises one optical signal output port. the PBS comprises three ports, one of the three ports of the PBS is configured to input a continuous light source, the other two of the three ports of the PBS are respectively connected to one port of the PR and a first port of the first coupler, and the PR is configured to perform polarization rotation on an optical energy output by the PBS; the other port of the PR is connected to one port of the first PT, the other port of the first PT is connected to a second port of the first coupler; or the other two of the three ports of the PBS are respectively connected to one port of the PR and one port of the first PT, and the PR is configured to perform polarization rotation on an optical energy output by the PBS; the other port of the PR is connected to a second port of the first coupler, the other port of the first PT is connected to a first port of the first coupler; a third port and a fourth port of the first coupler are configured to output single-polarization light in a same polarization state; wherein the second PT is placed between the third port of the first coupler and the second coupler, or between the fourth port of the first coupler and the second coupler, and the second PT is configured to control a phase of light passing through the second PT, so that there is a preset proportion of optical power output by the second coupler to peak power; the PD is placed between the third port of the first coupler and the second coupler, or between the fourth port of the first coupler and the second coupler, wherein the first PT is configured to control output optical power of the third port and the fourth port to be equal based on the obtained optical power information output by the PD; the radio frequency electrode is placed between the third port of the first coupler and the second coupler, or between the fourth port of the first coupler and the second coupler; the driver is configured to drive the radio frequency electrode; and the second coupler comprises one optical signal output port.