Filter element for purification filtration of injection water in oilfields. It has a tubular body with square holes densely perforated on walls, and upper and lower end caps connected to the ends of the tubular body with relative annular grooves. An external rhombic hole mesh cover is sleeved on tubular body, and its mesh cover and the two ends of the wave tooth cylinder are embedded in the relative annular grooves of the upper and lower end caps and adhered fixed. A plug-in pipe head is set on the outer side of the lower end cap and is connected with the tubular body. A sealing gasket is configured on the head. The production process of this filter element is simple, the product cost is low, the filtration medium is easy to select and configure according to the filtration accuracy requirements, and the plug-in configuration mode is convenient for filter element cleaning and replacement.An industrial filter element with a filtration accuracy of micron level. A folded filter layer is filled between the and outer center tube support of the filter element, and the inner and outer center tubes are perforated cylinders. The outer center tube has a coalescing layer on the outer side can coalesce the water in the oil liquid, and the outer side of the coalescing layer is a protective layer. The two ends of the filter element are covered with end caps and the filter layer is composed of a micron-level glass fiber filter paper layer as the base material, and the protective layer is composed of non-woven fabric and a net inside and outside. The water droplet coalescing layer is based on a glass fiber mat, and the inner side of the glass fiber mat is lined with non-woven, and the outer side is tied to the outer center tube with a protective net, and the outermost layer is sleeved with a cotton cover. The filter element of the present can work under high alkali concentration, high working pressure and high temperature oil liquid, and the filter material does not deform or puncture