When the MS 8 earthquake occurred in Wenchuan County of Sichuan on 12 May 2008, our piezomagnetic frequency measurement system about 1000 km away from the focus recorded the worldshaking natural disaster. Ninety days before the earthquake, the earth stress changed in a great magnitude, being indicative of the earthquake. Three mechanical components received 633.5 Pa, 1512 Pa and 4561.4 Pa, respectively. A few hours before the earthquake, the component directing the focus presented four pulsive anomalies immediately following the great earthquake. The platform can at the China Academy of Radiation and Protection Research, which is more than 1000 km far away from the focus, recorded the process of energy accumulation and surface deformation before the earthquake. This verifies the idea that the same stress state can be collected to a large extent at different sites of different faulting zones. This system is of high sensitivity, good performances and antiinterference ability, all these overcome disturb factors of this system employing pressure, resistance and inductance. The piezomagnetic frequency stress measurement system, which is not only installed on rocks of mountains but also in plain, is used to monitor rapidlychanging S wave and acquire boding information of earthquake so as to achieve the goal of forecasting earthquake. Therefore, the system of this kind will be of promising application.