Focal mechanisms of small and micro earthquakes are used as basic data for studies on regional stress fields and for other geodynamics studies. The Shaanxi region is at the intersection of several seismic zones, and abundant waveform data of small to microseismic events have been accumulated in recent years. This study uses the recently developed generalized polarity and amplitude technique (GPAT), together with a 2015 crustal velocity model of Shaanxi, to invert the focal mechanisms of 121 small and micro earthquakes with a range between M_L1.5 and M_L3.5 that occurred between April, 2011 and December, 2015, that were recorded by the seismic network of Shaanxi. Inversion results show that focal mechanisms of these events were mostly strike-slip and normal-fault types (64.5%) and thrust faulting types (22.3%). In addition, there is a good consistency between the focal depth inverted from the focal mechanism and the location depth. However, there is a difference between the moment magnitude and local magnitude, and this difference increases with a decrease in magnitude. Furthermore, compared with other study results conducted within the Weihe fault zone, this study verifies that normal fault types mainly control the focal mechanisms of earthquakes, and they are in a state of tensile stress.