Abstract: When carbon fiber reinforced polymer (CFRP) composites are manufactured, they often exhibit dimensional variations. In the subsequent assembly process, assembly gaps frequently occur at the connection interface. The CFRP-aluminum alloy double-bolt single lap joint was used as the research object. Quasi-static tensile test after forced assembly, combined with digital image correlation (DIC) technology and acoustic emission (AE) monitoring. At the same time, a UMAT subroutine was developed to accurately predict composite material damage for numerical simulation analysis. The effects of different forced assembly conditions on the bearing capacity, surface strain field deformation and damage evolution of CFRP-aluminum alloy double bolt connections were studied. The results show that the increase in gap height and length exacerbates the initial damage and strain concentration induced by forced assembly. It also intensifies secondary bending in the joint and increases the uneven bolt load ratio during tensile loading, accelerating damage propagation and ultimately reducing the ultimate load. Compared with ideally assembled CFRP-aluminum alloy double-bolt joints, when the gap length is 15 mm, the limit load reduction after forced assembly increases from 1.79% to 11.84% as the gap height rises from 0.2 mm to 1.0 mm. For a gap length of 20 mm, the corresponding reduction increases from 3.09% to 15.60%. When the gap height reaches 0.6 mm or above, the damage around the hole accelerates and the damage shows the characteristics of extending from a single damage stripe to multiple damage stripes. The final failure mode is manifested as the net section breakage of the main load-bearing bolts and the extrusion damage of the secondary load-bearing bolts.