PURPOSE: To enable luminous intensity and flashing to be properly controlled according to changes in conditions such as background brightness and environmental conditions by automatically observing those conditions and automatically entering obtained observation data.

CONSTITUTION: Data required to calculate a proper luminous intensity is automatically observed by environmental data observation parts 1a to 1n, retrieved by data input parts 2a to 2n, and calculated by an operation processing part 3 to determine a proper luminous intensity. The results are supplied to a control processing part 4 and if the proper luminous intensity has changed, a communication part 5 is informed that the luminous intensity should be switched. And if the switching of luminous intensity poses no problems, a switching enable signal is entered from an operation part 6. Further, proper luminous intensity data is output from a controlled output parts 7a to 7n in a controlled manner. This constitution provides an aeronautical ground light control device which allows luminous intensity and flashing to be properly controlled according to changes in conditions such as background brightness and environmental conditions.