A one-dimensional modulation continuous-variable quantum key distribution method is provided. The method includes transmitting, at a transmit end, a signal light field that passes through a first amplitude modulator and a first signal adjustment apparatus, and a reference light field, to an optical fiber combiner, and to a receive end through a quantum transmission channel. The method also includes separating, at the receive end, a quantum signal after the quantum signal passes through a second signal adjustment apparatus and an optical fiber splitter; and transmitting a separated reference light field and a separated signal light field to a measurement apparatus after the separated reference light field passes through a third signal adjustment apparatus and a phase modulator. Signal amplitude modulation and phase locking can be implemented by an amplitude modulator and a phase modulator, thereby simplifying the structure of the apparatus and reducing production costs.