The utility model discloses a quasi-distributed high voltage transmission line optical fiber monitoring network, comprising a transformer station control unit, a first wavelength division multiplexer, a second wavelength division multiplexer, a third wavelength division multiplexer, and two base tower monitoring subsystems; wherein the transformer station control unit comprises a communication control module, an optical signal demodulation module, and a fourth wavelength division multiplexer; the each base tower monitoring subsystem comprises a first optical path selection switch, a second optical path selection switch, a third optical path selection switch, a photoelectric conversion module, a controller, a first electro-optical conversion module, a second electro-optical conversion module, and a tower state sensor group. The quasi-distributed high voltage transmission line optical fiber monitoring network of the utility model raises the detection precision for lead aeolian vibration, lead temperature, and tower oblique angle of the high voltage transmission line, and raises the detection efficiency for the above parameters.