A method and device for selecting a detection area and an elasticity detection system, the method comprising: dividing organ tissue information to be identified into a plurality of detection sub-areas, and calculating a feature value of the organ tissue information within the detection sub-area (11); determining an organ tissue boundary area according to the organ tissue information to be identified (12); determining an organ tissue detection area according to the organ tissue boundary area and a preset feature value condition (13). The method determines an organ tissue boundary according to the organ tissue information, and automatically adjusts the detection area according to the organ tissue boundary.