The invention relates to the design and the manufacture of an intracavity frequency doubling microchip laser with high polarization ratio output. The initial polarization of frequency doubled laser in the conventional microchip laser structure is good, but because the frequency doubled laser is depolarized by the birefringence effect after being partially reflected into a laser gain medium (4), the polarization of the output laser is reduced. With the structure, because a medium film (7) blocks the frequency doubled laser from entering the laser gain medium (4), the depolarization influence of the laser gain medium (4) on the frequency doubled laser is eliminated so as to obtain polarized laser output with higher extinction ratio. Compared with the common design which utilizes a mode of inserting wave plates into a cavity to increase polarization output, the structure has better temperature adaptability and smaller overall heat productivity, has compact structure and low cost, and is more conducive to mass production.