Kevlar woven fabric rubber composite armor (WFRCA) is a type of add-on armor that usually consists of two steel plates with two Kevlar woven fabrics and a rubber layer in between. In this study, a theoretical model was developed to analyze the effect of the impact angles on the performance of the Kevlar WFRCA against the shaped charge jet impact. The calculation of the precursor length was discussed in detail. A series of X-ray experiments were conducted to analyze the disturbance mechanism and precursor length of the Kevlar WFECA against the shaped charge jet under different impact angles. Theoretical and experimental analyses showed that the greater the impact angle, the higher the tip velocity of the precursor and the shorter the precursor length. A microscopic study of the edge of the Kevlar woven fabric, rubber, and steel plates after the shaped charge jet impact was also conducted to evaluate the structure and composition. Several broken Kevlar fibers were embedded in the steel plate and the moving jet. This phenomenon can be used to further investigate the disturbance mechanism of the Kevlar WFRCA against the shaped charge impact.