Based on military operations involving UAV (unmanned aerial vehicles) reconnaissance and cross location in EW (Elctronic War) environments, a space and mathematics model was constructed. The definition of key indicators for the location ambiguity area and the proposal of an innovative calculation model, which is significant for accurate calculation of the ambiguity area was given. And the suggestions for military operations, such as strengthening monitoring and prevention of electronic countermeasure unmanned aerial vehicles, improving the positioning accuracy and countermeasures were proposed.