The invention relates to a novel method for preparing liquid fuel oil by catalytic cracking of biological oil with alkaline MNC-13 mesoporous molecular sieves. The method is characterized in that homemade alkali metal beta contained zeolite is taken as a guiding agent, synthesized triethylamine ionic liquid (HSO3-(CH2)3-Net3)(Cl) is taken as a template agent, and alkali mesoporous molecular sieves M-MNC-13, Ca-MNC-13, Ba-MNC-13 and Mg-MNC-13 are synthesized; the four kinds of synthesized molecular sieves are adopted as catalysts, catalytic cracking reaction is performed on the biological oil at the temperature ranging from 380DEG C to 430DEG C, the cracking rate of the biological oil can reach 90%, the yield of the liquid fuel oil can reach 70%, main ingredients of products are distributed between C12 and C17, and the performance index of the obtained fuel oil is equivalent to No.0 diesel oil. With the method, service life of the alkaline MNC-13 catalyst is well prolonged.