Su Ming was skilled in reading the changes in his opponents' thoughts and taking control of the weaknesses that came from their emotions. This was something which had already showed itself when he was hunting in Dark Mountain.
Since then, a thousand years had passed, and he had become even more proficient at it. His experiences had made his intelligence grow incredibly quickly. When Xing Ji Dao was shocked by the things happening around him and wanted to leave Arid Triad Expanse Cosmos as quickly as possible, why Su Ming used this to his benefit. He first offered help and activated the white ring so that his enemy would relax his guard.