Research conclusions:(1)The karst is the most unfavorable geological object and has huge harm and impact on the railway construction.(2)The major unfavorable geological problems of the mineral deposit and the mined一out area are crucial to the railway construction. The railway should keep away from the small mining areas as much as possible.(3)The major geologic structures of the mining area are the north一south，east一north and north一north structures. The railway also should keep away from the fault zone that stretches along the layer In the meantime，the height of the side slope should be strictly controlled，and the measures of reinforcing the side slope and cutting and preventions of the tunnel's bedding sliding and bias pressure should be taken.(4)The railway line's expansion program should as much as possible avoid changing or demolishing the building which would cause resurrection of geological disease.