To clarify the mechanical behavior of the cable saddle system in spatial cable-stayed suspension bridges, based on the structural characteristics of two types of spatial cable saddles, a theory of lateral force synthesis was derived, and the force patterns of the two types of spatial cable saddles were demonstrated. Taking a certain spatial cable-stayed suspension bridge as an example, a slice numerical model was established using ABAQUS to study the internal wire force characteristics, lateral pressure distribution patterns, and friction resistance composition of the two types of spatial cable saddles. The results show that the force pattern of the inclined plane saddle is the same as that of the plane saddle, and the lateral forces between the saddles are all caused by radial forces pointing to the center of the circle; for the spatial curved cable saddle, the radial force is approximately equal to the vector sum of the radial forces produced by vertical and horizontal bending, and in the spatial curved cable saddle, the outer pressure is greater than the inner pressure; the internal stress of the saddle groove is mainly concentrated in the local contact area, which is consistent with the classical Hertz theory; the force chain between the upper and lower layers of wires forms a diamond shape, with the force value gradually increasing with depth, but there is a sharp drop at the bottom layer; in the inclined plane saddle, the saddle base provides 86.4% of the friction resistance, and the saddle side only accounts for 13.6%; in contrast, the base of the spatial curved cable saddle provides 86.62%, and the saddle side provides 13.38%. In both types of spatial cable saddles, the contribution of the saddle base to friction resistance is much greater than that of the side.