The problem of mining under pressure in No.3 coal seam of Lu 'an mining area in Jindong coal base is prominent. The risk assessment of water outburst is the basis for effectively preventing water outburst disaster and ensuring the safety of mine production. Taking Licun Coal Mine as an example, the water outburst risk of Ordovician limestone water in No.3 coal seam floor was assessed and zoned by using five figures and double coefficients method and water outburst coefficient method. The thickness of the aquifuge at ZK4 borehole was small, the overall compressive strength of the aquifuge was low, and the Ordovician limestone water pressure was relatively high (5.18 MPa). Compared with the water outburst coefficient method, the five figures and double coefficients method considered more main control factors and could more accurately analyze the hidden dangers of Ordovician limestone water outburst. Therefore, the assessment results of the ' five figures and double coefficients method ' were selected as the final basis. The assessment results of the five figures and double coefficients method showed that the vicinity of ZK4 borehole in the western part of the study area ( 1.18 % of the total area ) was a non-through dangerous area, and the possibility of water outburst was greater. The rest of the area was a non-through relatively safe area, and the possibility of water outburst was very small.