Quantum data terminal applied to PSTN public network

The invention discloses a quantum data terminal applied to a PSTN public network. The input end of an analog-to-digital conversion module is connected with a telephone line; the output end of a digital isolation module is connected with the input end of a digital signal modulation and demodulation module; the digital signal modulation and demodulation module is connected with a control MCU through a UART interface; the quantum data terminal further comprises an RECIEVE module for voice playing, an MIC module for voice sampling and two amplification modules, wherein one of the amplification modules is used for audio amplification, and the other amplification module is used for amplifying signals acquired by a microphone; the control MCU is connected in series with one of the amplification modules and the RECIEVE module successively through a DAC; and the control MCU is connected in series with the other amplification module and the MIC module successively through an ADC. The quantum data terminal of the invention can realize smooth and clear communication and secure data transmission on a common PSTN, realize multi-protection for key SD cards, and can improve use security for users.