 During his career, he participated in successful campaigns against remnants of Western Tujue and against Goguryeo, with only one major flaw on his record which was an unsuccessful campaign against Tibetan Empire in 670, where another general in his army refused to listen to Xue's advice and charged ahead and caused the majority of the army to be lost.Xue Rengui was born in 614, during the reign of Emperor Yang of Sui, but his early activities were not recorded, other than that his wife had the surname Liu ().It was said that he was poor and was a farmer.