在万里长征途中,红军时时被敌人重兵围追堵截,却未中过一次埋伏,在国民党军设置的包围圈中都能准确地找到空隙钻出,这主要是依靠电台侦察及时掌握了准确的情报。当年红军电台有一条基本要求:“人在密码在,人亡密码亡。”遇到危急关头,首先砸电台毁电码。机要人员都会毁掉一切机密,直至牺牲也不泄露。国民党军队被红军成师、成旅地消灭时,却一再出现电台连同密码一同被俘获的现象。长征期间曾任红三军团长、红一方面军司令员的彭德怀说过:“凭着红军指战员的英勇和出色的侦察工作,才免于全军覆没而到达陕北。” During the Long March, the Red Army was constantly chased and intercepted by the enemy troops. However, it never missed an ambush. It accurately found its own void in the encircled encirclement set by the Kuomintang forces. This mainly depends on radio reconnaissance to grasp the accurate intelligence in a timely manner. At that time, the Red Army radio station had a basic requirement: “People are in the password, and the password dies.” “At the critical moment, first hit the radio to destroy the code. Confidential officers will destroy all secrets, until the sacrifice is not leaked. When the Kuomintang troops were turned into teachers by the Red Army and destroyed by brigades, the phenomenon of radio stations being captured together with the password was repeated. During the Long March, Peng Dehuai, head of the Red Army and Commander of the First Red Army, said: ”With the bravery and excellent reconnaissance work of the Red Army commanders and soldiers, it is only possible to prevent the entire army from slipping over to reach northern Shaanxi."