Geomagnetic storms are a common natural phenomenon in the earth's near space environment. In order to analyze the impact of geomagnetic storms on the pseudorange positioning performance of the Global Navigation Satellite System (GNSS), the pseudorange single point positioning performance of GPS positioning before and after the geomagnetic storm event on March 24, 2023 was analyzed based on observation data from five stations of the International GNSS Service (IGS). The results indicate that during geomagnetic storms, the accuracy of the ionospheric GPS-K8 correction model significantly decreases, affecting the positioning results of single frequency basic navigation users, but the pseudo range single point positioning accuracy is still within the standard range.