According to Baidu Encyclopedia, "Brothers of the Red Army, Walk Slowly" is a lyric classic folk song that has been sung in Jiangxi, an old revolutionary base area for decades. The lyrics were collected by Jiang Zhihua, the propaganda team of Jinggangshan Red Army, and were created during the strategic shift of 1927 with the Red Army. The tune was composed by Jiang Manfeng 1982, the original singer of the descendants of the Red Army martyrs, with the tune of local Hakka folk songs.
The lyrics are probably like this: Brother Red Army, walk slowly, be careful of stones on the road, touch my brother's toes and hurt my sister's heart, Brother Red Army, walk slowly, and so on.