A spacer structure for cross rollers comprises a frame and four protruding wings, the protruding wings are arranged in pairs on opposing sides of the frame and outwardly extend therefrom. The two inactive end surfaces of the roller are confined between the paired protruding wings of the spacer. The slenderness ratio of the roller is designed to be 0.7-0.98 for facilitating installation of the roller between the paired protruding wings of the spacer, and such arrangement can effectively reduce the contact area between the spacer and the roller. The paired opposite protruding wings can provide a stable positioning effect to the end surfaces of the roller.