In order to solve the metamerism phenomenon which happened in colorimetric gamut mapping, a new spectral gamut mapping algorithm was proposed based on point set model. Firstly，the colorimetric gamut and PQR gamut was constructed on the basis of device sample, and the whole spectral gamut of device was the combination of colorimetric gamut and PQR gamut. Then, the hierarchical mapping method was used to judge and mapping the target spectrum within Lab and PQR spaces. The munsell 1269 samples were tested， and the result showed that the color difference was 1.0079， and the spectral precision was 5.12%. The experiment data showed the new method has high spectral output precision, which can reduce the metamerism phenomenon effectively. Moreover, the result of mapping can satisfy the visual matching with the target under a variety of light source.