The invention provides an efficient polarization purifying device. The efficient polarization purifying device is composed of a wave plate heap, a quarter-wave plate and a reflector, wherein the wave plate heap is arranged obliquely, an Brewster angle is formed between the surface normal of the wave plate heap and the horizontal direction, then parallel light emitted by a laser can enter the wave plate heap with the Brewster angle, S polarized light is reflected, P polarized light is transmitted, and the quarter-wave plate is placed in the direction of S reflected light to enable the reflected S polarized light to shine on the quarter-wave plate vertically and the included angle between an optical axis and the horizontal direction to be 45 degrees; the reflector is placed behind the quarter-wave plate, the S polarized light is converted into the P polarized light after passing through the quarter-wave plate and the reflector, and then the P polarized light enters the wave plate heap with the Brewster angle. According to the efficient polarization purifying device, due to the fact that the reflector which is perpendicular to the wave plate heap is placed on the edge of the direction of emergent light formed after the reflected light passes through the wave plate heap, the emergent light is right in the horizontal direction; an extremely small number of elements are used, and single-direction-line polarized light with the high polarization degree, high polarization purity and high energy utilization rate is obtained.