Gently scrub and rinse the sweet potatoes under warm water. Pat dry with a clean kitchen towel. Using a fork, prick the skin of each potato.
Add 1 cup of water to a 6-quart Instant Pot or 1.5 cups for an 8-quart Instant Pot, and insert the trivet. Arrange 4-6 sweet potatoes in an even layer on the trivet.
Place the lid on the Instant Pot, seal, and close the release valve. Cook on high pressure based on the width of the sweet potato, about 15 minutes for 2-inch sweet potatoes and 35 minutes for 3-inch sweet potatoes.
Once the cycle is finished, allow it to sit for 10 minutes on natural release. Carefully open the pressure valve to release the steam away from you.
Remove the lid and let the sweet potatoes cool for 3 minutes before serving.