To maintain an automatic waterproof cover children umbrella, you should follow these steps:

1. Clean the umbrella regularly: Use a soft cloth or sponge to wipe the surface of the umbrella clean. You can use a mild detergent if the umbrella is particularly dirty. After cleaning, make sure to dry the umbrella completely before storing it.

2. Keep the umbrella dry: After each use, shake the umbrella to remove any excess water and leave it open to dry completely. This will prevent the growth of mold or mildew and keep the umbrella in good condition.
   

3. Store the umbrella properly: Store the umbrella in a dry and cool place. Avoid storing it in direct sunlight or damp areas. Also, do not store the umbrella when it is wet as this can cause damage to the mechanism.

4. Lubricate the mechanism: The automatic mechanism of the umbrella should be lubricated regularly to ensure smooth operation. Use a silicone lubricant spray to lubricate the mechanism.

5. Check for damage: Regularly inspect the umbrella for any damage, such as broken ribs or torn fabric. Replace or repair any damaged parts as soon as possible to prevent further damage.

By following these steps, you can ensure that your automatic waterproof cover children umbrella remains in good condition and lasts for a long time.