China is the country with the largest planting area and yield of watermelon in the world.In 2014, planting area and yield of watermelon was 1.852×10⁶hm² and 7.4843×10⁷t, accounting for 53.3% and 67.4% of the data around the world. The harvest period of watermelon is short, mainly between June to August. In order to avoid wasting, the watermelon deep processing products are developed, and watermelon juice is one of the most suitable one.Because of the presence of sensitive components, nutrients and flavor of watermelon juice were impacted greatly during processing. In this paper, aroma formation pathway of watermelon juice, key aroma compounds, and the effects of different processing methods (thermal and non-thermal processing) on the nutrition, sensory quality and flavor of watermelon juice were reviewed. The research direction was proposed about how to maintain the quality and flavor of watermelon juice during processing in the future.