In order to get the buckling load of deployable structures, stability of linear array deployable structures based on structure of SLE were studied. The paper established a structural instability limit load expression of SLE based on analysis of the elastic deformation of bar, which is applied to the array combination of deployable structure. Then the condition of the stability of this structure is obtained. Results indicate that: Buckling critical load were affected by the bar parameters such as the number of units, bar flexibility and position angle. With the increase of the number of units or the bar flexibility, structural stability gradually reduced; The position angle were affected by unit number, which cannot be used separately as the basis for judging structure instability.Deployable structure stability simulation analysis results and the theoretical analysis results are compared each other, confirming the correctness of the proposed method in this paper because of the experiment data well.