Plant chlorophyll content directly affects its photosynthesis and is closely related to the spectral characteristics of plants. In this study, summer maize was used as the research object, and the characteristics of chlorophyll content and its spectral characteristics under different water irrigations of summer maize at seven-leaf stage were studied by the water control method. The results showed that with the decrease of water irrigation, the chlorophyll content of the summer maize canopy leaves decreased and the spectral reflectance of the canopy increased. At the same time, the green peak position was "red shifted", but the red edge position was "blue shifted". There was a significant relationship of chlorophyll content with spectral characteristic parameters and vegetation spectral index. Based on these relationships, several hyperspectral inversion models of canopy chlorophyll content were established. The model validations indicated that canopy chlorophyll content was simulated better by vegetation index than single spectral characteristic parameter. The results provide the basis for rapid non-destructive determination of chlorophyll content in summer maize and drought monitoring of summer maize production.