When only single-point position information is provided, the commonly used combined navigation algorithms based on Kalman filtering still have limitations in error correction for inertial navigation systems. These algorithms struggle to comprehensively reflect the complex dynamic changes of inertial navigation systems and fail to effectively suppress the cumulative errors of such systems. Additionally, due to the insufficient research on the laws of navigation errors after single-point position correction, significant positioning and attitude errors persist in inertial navigation systems even after single-point position correction, severely affecting the accuracy and reliability of the navigation systems. The paper analyzes the internal mechanisms and laws of single-point correction through theoretical derivations, simulation verifications, and other methods. The research shows that the effectiveness of single-point position correction is related to the correction time. Correction performed when the heading error is zero yields the best results, achieving an error readjustment rate of over 90%. Moreover, the phase of the heading oscillation error is reset to zero after single-point position correction at any time. These findings can effectively guide subsequent research and applications of single-point position correction.