Aerodynamic design rules of unconventional layout loitering aircraft against the issue of stall in low speed flight were proposed in this paper. Using the SST k-ω two equations turbulence model, the stalling characteristics of the loitering aircraft were studied. Based on the low speed flow field of the loitering aircraft without the deflexion of the helm, aerodynamic parameters such as lift, drag, pitching moment and yawing moment in different workings were calculated. Analysis of the results shows that the loitering aircraft designed has good stalling capability whose critical angle of attack is 18 degrees. The loitering aircraft has good longitudinal and lateral stability under different angle of attack.