An intelligent outdoor sun shading device includes a shading system, an environmental sensor device and a functional controller. The shading system includes a supporting frame, a power source supported at the supporting frame, an awning frame suspendedly and movably supported by the supporting frame, and a sun shelter mounted to the awning frame to define a shading area under the sun shelter. The environmental sensor device is electrically linked to the power source and is installed to the shading system for detecting an environmental change of the shading system in responsive to the shading area thereof. The functional controller is electrically linked to the environmental sensor device and is operatively controlled the awning frame of the shading system, wherein when the functional controller receives a command signal from the environmental sensor device, the awning frame is automatically adjusted to regulate the shading area thereof in responsive to the environmental change of the shading system.