Abstract: The floor hidden faults with mine water bursting coefficient between 0.06 and 0.1 MPa/m have not been classified scientifically in combination with mining. Based on the characteristics of hidden faults in coal seam floor and the vertical relationship between the location of the top interface of the hidden fault and the "Three Underlying Belts", the hidden faults in coal seam floor are classified into three types:high, middle, and low from the perspective of mine water prevention of the floor. Through theoretical analysis and case analysis of water inrush, it is pointed out that the high hidden fault with the threat of water inrush has the characteristics of full penetration, suddenness, large water volume and high degree of harm. It is difficult to control afterwards. For high hidden fault, preventive measures such as grouting and strengthening the coal seam floor before mining are proposed; for low-hidden faults, different measures for grouting treatment before and after water inrush disasters are proposed. The research results provide an important reference for coal mine enterprises to deal with floor water inrush disasters caused by hidden faults.