The invention provides a physiological electric signal detection device based on a flexible non-contact electrode. The physiological electric signal detection device comprises the flexible non-contactelectrode, a shielding line and a signal acquisition module, wherein the signal acquisition module comprises an impedance matching unit, an anti-aliasing filter unit and an analog-to-digital conversion unit; the flexible non-contact electrode is used for detecting potential change of human body surface through a coupling capacitance which is formed by the flexible non-contact electrode and humanbody skin; the shielding line is used for transmitting a potential change signal to an input end of the impedance matching unit and for conducting electromagnetic interference shielding on the potential change signal in a transmitting process; the impedance matching unit is used for conducting signal amplifying processing on the potential change signal; the anti-aliasing filter unit is used for conducting filtering processing on the amplified potential change signal; and the analog-to-digital conversion unit is used for conducting analog-to-digital conversion processing on the amplified and filtered potential change signal, so that a physiological electric signal of human body is obtained. The detection device provided by the invention has the advantages of being comfortable to wear, goodin shielding performance, strong in anti-interference performance, simple in circuit structure, high in precision and low in cost.