Mo was born in Bantang Hamlet 板塘屯, Bantang Village 板塘村, Chuanshan Town 穿山镇, Liujiang County, Liuzhou City, Guangxi Province, China.
His first major result was a gold medal at the 2013 World Youth Championships, where he ran a personal best and world youth leading time of 10.35, beating Ojie Edoburun in a photo finish.