The present paper aims to introduce the authors' simulation of the instable failure process of seam floor above confined aquifer under mining. Our simulation was done numerically based on the theory of the flow and damage coupling by using F-RFPA 2D (Coupling System of Flow & Solid in Rock Failure Process Analysis). The paper also made a discussion with F-RFPA 2D the water outburst mechanism from the seam floor and predicted the position of the water outburst. In accordance with the geological conditions of...