A method for screen unlocking, a method for image acquiring, and an electronic terminal are provided. In the method for screen unlocking, a most frequently used debug parameter is counted according to recorded debug parameters used for image selection in the most recent N instances. Auto-adjustment is performed on the debug parameters from the most frequently used debug parameter, and an image current acquired is debugged with the debug parameters adjusted, to obtain debugged images. A target fingerprint image is selected from the debugged images. Whether the target image satisfies an unlocking condition is identified and a screen of the electronic terminal is unlocked when the unlocking condition is satisfied. Accordingly, a method for image acquiring and an electronic terminal are also provided.