Polymer with low dielectric constant and molecular structure design method capable of reducing dielectric constant of polymer

The invention discloses a polymer with a low dielectric constant and a molecular structure design method capable of reducing the dielectric constant of the polymer. A straight-chain rigid group is introduced into a meta-position of a side group benzene ring or diphenyl chain segment structure by using the designability of a molecular chain side group of a polymer; and a free volume hole with a larger size is formed in the material through loose rotation of the side group benzene ring to inhibit molecular chain deposition, thereby reducing the dielectric constant of the polymer material. The design method is simple, is suitable for a common high-performance polymer material, can be applied to preparation of a low-dielectric polymer material, is suitable for the field of new and high technology industries such as electronics, microelectronics, information and aerospace and is especially suitable for the field of super-large-scale integrated circuits.