The application of thin composite material laminate secondary bonding technology to the main load-bearing structure of small UAV wings has important engineering applications for reducing the manufacturing costs of wing box section. A single-lap structural tensile shear test was carried out using a 2mm sheet made of carbon fibre twill. The suitability of three different types of adhesive for the sheet was analysed, as well as the effect of adhesive thickness and laminate lay-up angle on the strength of the secondary glue joint, and the simulation was verified by ABAQUS software. The results show that: using SY-23B epoxy structural adhesive, the adhesive layer thickness is 0.2mm, the lay-up method is [(0/90)]8-[(0/90)]8, the bonding performance is optimal, the structural shear strength can reach 18.2MPa, to meet the small UAV stress box section bonding strength requirements, the secondary bonding formed wing stress box section has the advantages of light weight, low cost.