Luo was born in a village in Hengshan County, Hunan Province. He joined the Chinese Communist Youth League in April 1927 and the CCP later that year. During the Long March he served as security chief.
After World War II, Luo Ronghuan served as the political commissar of Lin Biao in Manchuria during the Chinese civil war. Unbeknownst to outsiders, Luo's contribution to the communist victory in Manchuria and hence to a great degree, in the mainland China was far greater than what was previously publicized, and in fact, greater than that of Lin Biao. The reason is that people often overlooked Luo's political contribution by concentrating on Lin Biao's military victories. However, Lin Biao, or any communist commanders would never be able to achieve any military victory if there is not any strong and stable political support from the troops and the general populace. This is where Luo's importance proved to be critical: Luo's skillful political work ensured the troops' loyalty and popular support of the communists. After the end of World War II, the communists demilitarilized more than a million of its troops. However, the communist demilitarization was far from the peaceful demilitarization of the nationalist counterparts, and in fact, the communist demilitarization was part of Mao's class struggle in which most of these demilitarized troops and cadres were persecuted. The reason of persecution of the troops and cadres within their own rank was simple: despite their dedication to communism, those troops and cadres were from well to do family backgrounds. As a result, the communists were not only in danger losing the popular support, but also face alienation and defection within its own ranks. Luo Ronghuan was intrumental in stopping the wide spread persecution and thus saved the communists in Manchuria from losing the popular support, as well as supports within its own ranks, thus strengthened the communists, ensured Lin Biao's later military victories, and Luo did all of these against Mao's wishes. It was not after witnessing Luo's success did Mao started to praise Luo's effort. As a result of Luo's success, the defection and desertaion among communists in the entire Manchuria only numbered around 60,000, while in other communist controlled region such as in Shandong alone, the defection and desertion numbered more than 300,000 according to Mao's own admission, and the communist force in Shandong was much smaller than that of Manchuria. Luo's bravery of rejecting persecution of Mao's class struggle ideology had saved communist in Manchuria from certain failure.