The invention discloses a method for determining the orientation degree of oriented silicon steel. The method comprises the following steps: step one, cutting a steel plate into a plurality of rectangular narrow strips, and stacking the rectangular narrow strips to form a combined sample, wherein a face to be detected of the combined sample consists of cross sections, vertical to the rolling direction, of the rectangular narrow strips; step two, measuring the crystal axis density of crystal grains (uvw) of the face to be detected by an X-ray diffraction instrument; step three, substituting the measured crystal axis density of the crystal grains (uvw) of the face to be detected into the formula, G=P[001]/sigma P[uvw], to calculate the orientation degree of the combined sample (2), wherein G is the orientation degree of the combined sample, and P[001] and P[uvw] are crystal axis densities of the measured crystal grains (001) and other crystal grains (vuw) respectively. Compared with the prior art, the method has the advantages in statistical significance, greatly improves the working efficiency, and can be widely applied to the production and research fields of oriented silicon steel.