The utility model relates to an internal filter screen of a crude oil filter, and applies to filter impurities in oil field crude oil or a well fluid transport process. The internal filter screen is characterized in that an upper top cover and a down bottom cover are connected together through four double-end bolts, and coarse filter screens and a thin filter screen are arranged between the upper top cover and the lower bottom cover; an inclined plate with an inclination being 45 degrees is arranged between the upper top cover and the lower bottom cover, the inclined plate is of an elliptical ring shape, and the four double-end bolts pass through fixing holes in the inclined plate; and the thin filter screen is arranged between the lower bottom cover and the inclined plate, the coarse filter screens are two circular arcs, one of the coarse filter screens is arranged between the lower bottom cover and the inclined plate, and the other coarse filter screen is arranged between the upper top cover and the inclined plate. The internal filter screen provided by the utility model has the effects that the impurities in oil field crude oil or a well fluid are filtered, the consumption of the filter screen is reduced, the cleaning operation is simple, the labour intensity is reduced, and the operating efficiency is improved.