The invention discloses a spacer with a set height and a manufacturing method thereof, and relates to the technical field of optical filters. According to the spacer, a first optical filter layer is formed on a black matrix of a substrate of a colored optical filter piece, a second optical filter layer is formed on the first optical fiber layer, a third optical fiber layer is formed on the second optical filter layer, and a fourth optical filter layer with a certain thickness is formed on the third optical filter layer to obtain the spacer with the set height. The thickness of the colored optical filter piece is increased due to the fact that the fourth optical filter layer is additionally arranged on the third optical filter layer, influences on the thicknesses of other optical filter layers are not caused, the thickness of the colored optical fiber piece can reach a set value under the condition that display is normal, the manufacturing process is simple and the spacer and the manufacturing method are suitable for large-scale application.