The invention discloses a two-side offset paper suitable for paper bags and a preparation method thereof, the two-side offset paper comprises 25%-50% of masson pine, 50%-75% of broad-leaved wood, 55.3 g / m < 2 >-64.8 g / m < 2 > of fortified rosin size, 58.4 g / m < 2 >-66.9 g / m < 2 > of starch, 59.8 g / m < 2 >-63.4 g / m < 2 > of water glass, and AKD (Alkyl Ketene Dimer) glue. The proportion of the AKD glue is 56.1 g / m < 2 > to 63.3 g / m < 2 >. According to the two-side offset paper suitable for the paper bag and the preparation method of the two-side offset paper, starch particles are dispersed in water to form suspension potted base paper through starch added through a spraying method, and the starch particles are wrapped by fibers, so that the stiffness, tightness, tearability and interlayer bonding strength of the paper industry are improved, and the water permeability of the paper industry is greatly reduced; through the starch and the AKD glue, the galling speed of the surface of finished paper can be increased, and the prepared two-side offset paper is small in flexibility, uniform in ink absorption, good in smoothness, compact in texture, non-transparent and high in water resistance.