Research On The Issue Of Military Intelligence Before Customs Clearance

At the end of the Ming Dynasty,Nurhachi fought against the Ming Dynasty with13 sets of left armor.The Ming Dynasty successively lost the Liaoshen region centered on Shenyang and Liaoyang,and then lost most of Hexi and Liaodong Peninsula.The continuous growth of Houjin finally successfully opened the gate of Shanhaiguan,and then entered the pass to unify the world.The victory of the war of the Late Jin Dynasty（Qing Dynasty）against the Ming Dynasty lies not only in the bravery of the soldiers of the eight banners,but also in their successful intelligence work.This paper discusses the military intelligence work before the Qing Dynasty entered the customs from three aspects.The first part starts from reviewing the intelligence work in ancient China and several famous intelligence wars during the confrontation between Ming and Jin（Qing）,in order to provide an appropriate historical basis for the following.The second part expounds the implementation of military intelligence activities before the entry of the Qing Dynasty from the tools of intelligence personnel and military intelligence early warning transmission.Based on historical facts,the third part summarizes and analyzes the characteristics of military intelligence activities before the entry of the Qing Dynasty and Its Enlightenment to modern national security and national defense construction.