Wash the sweet pumpkin thoroughly and remove the skin and seeds.
Cut the sweet pumpkin into bite-sized pieces.
Boil water in a pot and steam the sweet pumpkin.
Place the cooked pumpkin in a bowl, let it cool, then mash it.
Finely chop the onion and cucumber.
Add the chopped vegetables, soy milk mayonnaise, salt, and pepper to the mashed pumpkin and mix well.
Serve in a salad bowl to finish.