Northwestern Engineering Institute

In 1938, due to the Japanese invasion of China, many universities in the occupied east evacuated to "Free China" in the western hinterland. Among those that fled to Shaanxi, the National Beiyang Engineering Institute, the Engineering School of Beiping University, the Engineering School of the National Northeastern University, and the (private) Jiaozuo Engineering Institute were combined to form the National Northwestern Engineering Institute in Hanzhong, a city surrounded by mountains. In 1946, after the surrender of Japan, Northwestern Engineering Institute was relocated to the city of Xianyang.

East China Aeronautics Institute

In 1952, to meet the demand for concentrated aeronautics research, the departments of aeronautical engineering of the former National Central University (later known as Nanjing University), Jiaotong University and Zhejiang University were relocated to Nanjing and combined to form the East China Aeronautics Institute. This institute was relocated to Xi'an and renamed the Xi'an Aeronautics Institute, which is the second predecessor of the NPU, in 1956.

In 1957, the Northwestern Engineering Institute and the Xi'an Aeronautics Institute were merged to form NPU, which concentrated its research efforts on defense technology for aeronautics, astronautics and marine engineering.

People's Liberation Army Military Engineering Institute

In 1970, due to deteriorating relations with the former USSR, the People's Liberation Army Military Engineering Institute, which was located in Harbin, was disassembled. Many of its departments were relocated from the city near the China-Soviet border; among these, its Department of Aeronautical Engineering (the third predecessor of NPU) was moved to Xi'an and merged with the other two predecessors to form NPU.