Hands-free call device capable of cancelling echo and control method thereof

The invention discloses a hands-free call device capable of cancelling echo and a control method thereof. The hands-free call device comprises a voice input module and a voice output module, wherein the voice input module comprises a microphone, a differential input circuit, a pre-amplifier circuit, a second coder-decoder and an echo cancelling module; and the voice output module comprises a DSP (Digital Signal Processor) chip, a first coder-decoder, a driving power amplifier circuit and a loudspeaker. The hands-free call device supports true full-duplex communication, is free from half-duplex inhibition, is capable of processing an echo tail length being up to 400ms through the echo cancelling module, is suitable for various space environments, is capable of processing very strong echo and realizing rapid convergence and re-convergence, is free from echo leakage when an echo path is changed, and has the effects of de-noising, resisting squeaking and realizing automatic gain. The hands-free call device and th