Centralizer is a guide device installed outside the wellbore, belonging to cementing tools. It has a wide variety of types and can be divided into integral, segmented, roller, slider type, etc. according to structure. It can be divided into reinforced nylon, powder alloy, reinforced engineering plastic, carbon fiber, metal type, etc. Different structures and materials of centralizers are also suitable for different types of oil wells. The commonly used types of centralizers include spiral centralizers, roller centralizers, oil rod centralizers, etc.