Abstract: The imaging algorithms in frequency domain of bistatic synthetic aperture radar (SAR) are a hot topic in the field of SAR imaging at present. Because the range history of bistatic SAR has the form of double-square-root, the analytic two-dimensional spectrum express can not be deduced using the principle of stationary, which brings a certain difficulty to research on imaging algorithms of frequency domain. The impulse response of a point target is introduced, and the main-lobe width, peak side-lobe ratio and integrated side-lobe ratio are utilized to perform quantitative evaluation of point target’s impulse response obtained by extended LBF (ELBF), method of series reversion (MSR) and two-dimensional principle of stationary phase (2D PSP) respectively. Meanwhile, taking spaceborne/airborne hybrid bistatic SAR imaging for example, two-dimensional focused results using different spectrum model is processed, which furtherly validates the precision of three kinds of spectrum model.