The invention discloses a material preparation process for preparing dissolving pulp by modifying bleached bamboo-wood composite pulp. The process comprises the steps of preparing raw materials, dispersing, splicing, soaking and the like, specific process steps and process control parameters are adopted for composite material of the bleached wood pulp and the bleached bamboo pulp, so that the quality of a final product is improved, the energy is saved, the emission is reduced, the content, the yield and the whiteness of alpha cellulose in the finished product are improved, the ash content of the alpha cellulose is reduced, and a cost control of chemical liquid medicine is facilitated, a subsequent cooking heating curve is stable, degree of polymerization is uniformly decreased, the obtained semi-finished product is suitable for all kinds of cooking manners, and the application range is wide.