Abstract: Stratospheric airship-laden radar system has more advantages for detect near-space targets than ground-based radars, but there is also the issue of radar detection performance affected by the airship movement,the echo form of the airshipborne radar should be analyzed in the light of the characteristics of the stratospheric airship motion. In this regard, this paper starts with the difference of the speed of airshipborne radar antenna array elements, the calculation model of the airshipborne radar antenna array element motion and the calculation model of the airshipboard radar echo are established respectively. According to the established model, the influence of airship sway on radar signal is analyzed and the influence of different factors on the antenna array element velocity is calculated, echo simulations were respectively carried out with the situation in maximum and minimum antenna element velocity differences, the results show: when the airship in motion, airshipborne radar detection effect decreases with the target distance increases, but the decreases in different detection direction is different.