Abstract: Toughness of mineral polymeric material can be improved by the mixture of cellulose fiber. The way of adding cellulose fiber was discussed by using fly ash and metakaolin for pretreatment to cellulose fiber. Cellulose fiber before and after pretreatment were added to mineral aggregate materials at different quantities to investigate the toughness effect of cellulose fiber on fly ash-metakaol in mineral polymeric materials. The results show that the toughness of synthetic mineral aggregate materials after mixing wood fiber and alkali excitation agent can achieve the best effect; Cellulose fiber after pretreatment is closely surrounded and supported by fly ash and metakaolin; the effect of toughness is best when the addition amount cellulose fibers with and without pretreatment is 0.5 % with the pretreated cellulose fiber of fly ash being the optimum; toughness of mineral polymer material decreased with the increasing of the amount of wood fiber with pretreatment and without pretreatment,.