What to make of the design of the ringed spaceship in Wandering Earth?

In fact, in the universe, after a spaceship accelerates to a predetermined speed, it no longer needs the thrusters to work. Instead, the movie shows the state of the ship by whether the thrusters work or not, which is not scientific. The ship only needs to activate the thrusters when it reaccelerates after decelerating (e.g., when it hits an asteroid in the movie), when it adjusts its course, etc.