“Tunnel Effect”, being an important theory in artistic creation and of great benefit to our understanding of the “Shadow” and “Light” in artistic works, explains the “Totality” principle by borrowing what people see and what they feel when a train goes through a cave. The novel Gone with the Wind is the masterpiece of the female American writer Margaret Mitchell, Which has enjoyed world wide popularity upon its publication, and its heroine Scarlett O Hara has become an unforgettable character. By applying the “Tunnel Effect” to analyze Mitchells way of handling the “Shadow” and “Light” when describing Scarletts three marriages, we can have deeper insights concerning the novels source of charm and beauty of rhythm.