The invention provides a heterodyne detection device based on light injection locking and a light phase-locked loop, which comprises a polarization tracking section, a heterodyne detection section anda down-conversion section, and is characterized in that the heterodyne detection section comprises an injection locking section, a coherent detection section and a light phase-locked feedback loop; the injection locking section comprises a first polarization-maintaining optical branching device, an optical phase shifter, a polarization-maintaining circulator, a local laser and a second polarization-maintaining optical branching device; the coherent detection section comprises a polarization-maintaining 2 * 2 3dB coupler, a balance light detector pair, a low-noise trans-impedance amplifier anda first power divider; the optical phase-locked feedback loop comprises a first amplifier and a loop filter; the down-conversion section comprises an ultra-narrow band-pass filter, a second amplifier, a second power divider, a phase shifter, a pi/2 power divider, a third amplifier, a third power divider, a first mixer, a second mixer, a first low-pass filter and a second low-pass filter. Heterodyne detection is adopted, frequency synchronization of LO light waves and main control light waves is achieved, the receiver achieves zero frequency deviation, phase noise is small, and output signalsare stable.