To study the influence of the initial stiffness defects of assembled joints on the stability of cable-stiffened latticed shells, the nonlinear full-range analysis of cylindrical cable-stiffened latticed shells was carried out, considering joints with same stiffness deviation and random stiffness deviation. The instability mechanism and failure modes of the structures were analyzed. The instability mode identification method was proposed based on the asymmetry degree β of joint stiffness, providing a basis for the control standard of initial stiffness defects. Results show that for the cylindrical cable-stiffened latticed shells supported along the two longitudinal sides, the stability bearing capacity of the structure with semi-rigid joints was 15% lower than that of the structure with ideal rigid joints. Besides, the cylindrical cable-stiffened latticed shells with semi-rigid joints were more sensitive to random stiffness defects. When the maximum amplitude of the random stiffness defect was 2% of the initial stiffness, the ultimate bearing capacity decreased by at most 36% compared with the semi-rigidly connected structure without defects. Due to the asymmetric distribution of jonit stiffness in cylindrical cable-stiffened latticed shells, two modes of positive symmetric and antisymmetric instability might occur. When the asymmetry degree of joint stiffness was greater than 1, the structure changed from positive symmetric instability to antisymmetric instability, and the bearing capacity decreased by about 30%.