The invention discloses a flexible power generation element, a self-driven voiceprint sensor and a voiceprint recognition security system. The flexible power generation element comprises a first component, a second component and a third component; the first component comprises a first metal conducting layer and a first electrode formed on the edge of the first metal conducting layer; the second component comprises a high-molecular polymer insulating layer and a porous structure in the high-molecular polymer insulating layer; the third component comprises a second metal conducting layer and a second electrode formed on the edge of the second metal conducting layer; the first component, the second component and the third component are in seamless close fit, and the second component is compressed or expanded by a sound pressure generated by sound in the second component to generate an AC signal containing sound information; the self-driven voiceprint sensor is formed by one or more flexible power generation elements; and the voiceprint recognition security system comprises a voiceprint sensor, a filtering and amplifying unit, a data collection unit, an analyzing and processing unit, a control unit and a response terminal, which are connected in sequence. The voiceprint recognition security system provided by the invention has the advantages of compact structure and high voiceprint recognition rate.