How to solve the problem of central air conditioning blowing upward and not being adjustable in winter

The central air‑conditioning vents have no adjustable deflector, so in winter the warm air gathers at the top of the room, making it difficult for people at the bottom to feel the temperature. How can this be resolved?

It’s not that exaggerated; I think it’s fine.
You can turn up the temperature or buy an electric heater.

Buy a small fan and blow upward along one side of the wall.