The invention discloses a fly-ash mine fiber paper pulp and a preparation technique thereof. Specifically, slag, silica and coke are mixed for granulation as required, coke feed ratio is determined between 0.12 and 0.23, the mixture is melted at a high temperature, mineral fiber is formed after the fusant of the mixture is swung by a centrifuge, and then fly-ash mine fiber pulp is obtained after the dispersed softening, deslagging, concentration and coarse pulp dehydration of the mineral fiber. The preparation technique is applicable to mineral fiber pulp for producing paper and can replace or partially replace paper-making wood pulp, thus saving crude wood, protecting forestry resources and reducing cost by 20 percent compared with organic plant fiber paper making. In addition, the invention has simple technique and environment-friendly production process.