Abstract: In order to explore the low frequency ranges of the multiple bandgaps of a new type periodic structure, double beams in parallel with periodically locally resonant oscillators with two degrees of freedom are proposed. The flexural vibration band structure of the infinite system is analyzed using the plane wave expansion method. The transmission properties of the corresponding finite system are examined by using finite element simulation. The bandgap form mechanism is studied in terms of the eigenmodes and transverse deformation pattern. The simple formulas of the start and ending frequencies of the bandgaps are derived based on the eigenmodes and the effects of the structural parameters on the bandgap characteristics are studied. The existence of the band gap characteristics is verified experimentally, and the accuracy of the theoretical predictions is proven. The results show that by only tuning the stiffness of the springs connected with the two beams, the bandgap can be effectively adjusted, which provides a reference for vibration reduction of double beams in parallel with oscillators with two degrees of freedom.