To deal with the interception performance of the spaceborne sensors with narrow field of view in low earth orbit constellation, a simplified interception probability calculation method was proposed based on Gauss ellipsoid of the guided information error, according to the analysis of the field of view of the sensor. Moreover, the calculation complexity and influencing factor of interception probability were analyzed. The simulation results indicate that the proposed calculation method could reflect the interception performance rationally and hasn’t operation burden. Furthermore, the influencing factor analysis could provide necessary references to the real application.