The invention discloses a nondestructive detection method and a device for an anchor rod. The method adopts an anchor rod detection device employing plastic bullet excited vibration, and the device includes an anchor rod (4). Specifically, an excitation surface (5) is disposed at an exposed end of the anchor rod (4), a plastic bullet shooting vibration exciter (3) able to shoot plastic bullets is disposed at a place that is 0-20cm away from the excitation surface (5) and is directed at the excitation surface (5). The excitation surface (5) is provided with a receiving sensor (2), which is in connection with an anchor rod detector (1) by a connecting line (6). Plastic bullet excited vibration is adopted in the invention, elastic waves can be generated when a bullet hits against the excitation surface. The elastic waves can acquire excitation vibration energy and frequency needed for anchor rod detection, and also can reduce mechanical vibration waves attached to the anchor rod maximumly. Thus, an optimal excitation vibration mode is provided for anchor rod detection.