A controller unit for electrically controlling an outdoor shading device having an awning frame and a supporting frame, includes a operation housing mounted on the supporting frame of the outdoor shading device, wherein the operation housing has a surrounding wall; a control panel being supported on the surrounding wall of the operation housing at a predetermined location for controlling one or more electronic appliances of the outdoor shading device; and an electronic appliance holder assembly for holding at least an electronic appliance thereat and electrically linking with the control panel, wherein the holder assembly is located on the surrounding wall of the operation housing and being arranged that the electronic appliance holder assembly is located at an opposed side of the surrounding wall with respective to the control panel.