Disclosed is a system for automatically measuring a discharge in real time based on a CCTV image. The system includes: a water depth measurement device filtering water depth data measured by a measurement means with a local linear regression-based bivariate scatterplot smoothing technique through flexible bandwidth application to calculate the water depth of a stream; an image acquisition device acquiring a continuous image of a flow speed measurement side of the stream; an image analysis PC using an image of the image acquisition device to measure the surface flow speed in real time and receiving a measured water depth from the water depth measurement device to measure the discharge in real time with cross-section data; and a discharge calculation and management server for transmitting and displaying a real-time discharge measurement result based on a web.