Inversion of phytoplankton chlorophyll-a concentration of inland water body is hotspot and difficulty problem inwater quality remote sensing. This paper provides a method to resolve this problem. Basing on the characteristic spectralanalysis of chlorophyll-a, suspended matter, chromatic dissolved inorganic matter and pure water molecule in inland waterbody, the three-band model was spectrally tuned in accord with optical properties of Lake Taihu to optimize spectral bandscombination for accurate chlorophyll-a concentration estimation. The remarkable linear relationship was established betweenanalytically measured chlorophyll-a concentration and the three-band model. Depended on the favorable theory basis of themodel developed, this method achieved good result with high determination coefficient 0.8358 and low root-mean-squareerror (3.816 mg/m³), which was proved to be an useful tool to retrieval chlorophyll-a concentration in very turbid, hyper-eutrophicinland waters.