The invention belongs to the preparation field of glass fiber reinforced plastics, and discloses a glass fiber reinforced plastics based on 2,3-butanediol, and a preparation method thereof. The glass fiber reinforced plastics have the following repetitive structure unit defined as in the description, wherein R1 is selected from -CH(CH3)-CH(CH3)- and -(CH2)o-; R2 is selected from -(CH2)p- and ortho-position-substituted benzene; n is from 1 to 100; m is from 1 to 100; o is from 2 to 13; and p is from 0 to 11. The invention also discloses the preparation method of the glass fiber reinforced plastics based on 2,3-butanediol. Products obtained by the method have light weight, high strength, good corrosion-resistant performance, thermal performance and electrical performance, and have wide applications in aviation, rocket, spacecraft, high voltage, insulation, heat-insulation and corrosion-resistant containers, and other products required to lighten self-weight.