A holographic display panel with precise control in the wavelengths of projected light, and therefore sharpness of image, includes a light source and a filter layer. The light source emits at least a first color light and a second color light. The filter layer is located on an optical path of the first color light and an optical path of the second color light. The filter layer includes first and second filter units. Each of the first filter units filters and restricts wavelengths of the first color light, each of the second filter units filters and restricts wavelengths of the second color light.