Even though the universal gravity force has been formulated and used for more than three hundred years, the cause of the universal gravity force has not been fully understood. This paper proposes a substantial aether model to derive universal gravity force based on Newton's laws of motion and Bernoulli's equation. The authors suggest that every aether particle has a mass and occupies a volume in space. Every aether particle has translational movement and particle spin movement. The particle spin movement does not produce the universal gravity force. The translational movement is similar to the gas particle moving in the air and produces aether pressure. The difference of aether pressure generates an aether flow velocity. The difference of aether flow velocities creates a pressure difference according to Bernoulli's equation. The summation of aether pressure difference around an object is shown to be the universal gravity force. A detailed derivation of universal gravity force from the proposed substantial aether model is presented in this paper to show the validation of this model.
