Glass fiber with low permittivity

The invention discloses a low-dielectric constant glass fiber, which comprises the following parts: 50- 60% SiO2, 6.0-9.5% Al2O3, 30.5-35% B2O3, 0-1.5% Na2O, 0-1.5% K2O, 0-1.5% Li2O, 0-5% CaO, 0-5% MgO, 0.5-2.5% ZnO, 0.5-5% TiO2. When the frequency is 1MHz under indoor temperature, the dielectric constant is 3.9-4.4, which is fit for high-density wiring circuit board.