The present invention relates to the field of quantum communication, especially a quantum key distribution device that can be configured with multiple protocols. It uses the simplified Faraday-Michelson interference ring in combination with the intensity modulator to perform timestamp encoding in a chopping manner. The phase modulation is completed with a Sagnac ring device composed of a single-polarization phase modulator, a polarization beam splitter and a Faraday rotator, so as to achieve the purpose of composite encoding and decoding, thus realizing a quantum key distribution device which can be configured with multiple protocols and multiple decoy state schemes. This device can be compatible with multiple protocols including BB84 protocol, the reference frame-independent protocol, the six-state protocol and SARG protocol and is characterized with polarization-independent phase modulation and low system complexity.