The orientation accuracy of three component station seismometers is very important for modern seismology research. Modern seismic studies rely heavily on precise three-component broadband observations. Similar to time travel, three dimensional particle motion is a key factor provided by a seismogram. It forms the basis of many functions, such as shear-wave splitting, receiver function, and surface and normal mode studies. Three component records are often rotated to isolate longitudinal, radial, and transverse motions. A critical parameter for performing rotation is the geographical orientation of the two horizontal components (BHN and BHE). Because the orthogonality between components of modern broadband instruments is accurate to a fraction of a degree, what really affects a correct rotation is the orientation of the BHN component, which could deviate from the true north direction. Knowledge of the orientations of the two horizontal components is thus important to perform a correction rotation. The particle motions of teleseismic P waves recorded by the network were analyzed and used to estimate the north component azimuth of each station. An SNR-weighted-multievent method was introduced to obtain component azimuths that best explain the P-wave particle motions of all the events recorded at a station. This method provides robust estimates including a measurement error calculated from background noise levels. In this study, the component azimuths of the seismic stations in Gansu province were rechecked using the P-wave particle motions of 549 M_S > 6 teleseismic events from August 2007 to September 2013. Robust estimates were provided including a measurement error calculated for each station in the time series. The azimuths calculated in this study are very consistent with the results of Niu (2011), which implies that the stations of Gansu province have some problems with misorientation. The SNR-weighted-multievent method can be used to effectively check the seismometer stations horizontal azimuth deviations. Therefore, we provide deviation value of the azimuth including a measurement error calculated for each station in the time series to be taken into account for any rotation based seismic studies.