The invention relates to an emergency monitoring and early warning method for red tide disasters at the coastal region of South China, which comprises the following steps: reflectivity data are obtained based on corresponding water spectroscopic data, fluorescence height is calculated by using the obtained reflectivity data, a water particulate matter backward backscattering coefficient is extracted by adopting a 6-wave band algorithm, chlorophyll concentration is estimated by adopting the 6-wave band algorithm based on the obtained water particulate matter backward backscattering coefficient, and finally, the breakout probability of red tides can be read according to the obtained fluorescence height value, the obtained water particulate matter backward backscattering coefficient and the obtained chlorophyll concentration. The emergency monitoring and early warning method has good discriminating capability for breakout probability of the red tides at the coastal region of South China and provides decision support for coping with red tide events.