•Novel D–π–A polymers bearing thiophene and TPA derivatives are synthesized.•Different acceptor pendent groups exert different impact on polymers’ property.•All polymers display excellent solubility in low-boiling point organic solvents.•Polymers have both fluorescence effect and electrochromic effect.•Polymers show large transmittance changes in near-infrared region.A series of novel donor–π-bridge–acceptor type conjugated polymers bearing 3,3-bis((2-ethylhexyloxy)methyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine and triphenylamine (TPA) derivatives are synthesized via Stille coupling. The optical, fluorescent, electrochemical, spectroelectrochemical and electrochromic switching properties are characterized. The polymers display excellent solubility in low-boiling point organic solvents. Different electron-withdrawing pendent groups attached on TPA exert great influence on polymer’s fluorescent and electrochromic properties. All polymers show large transmittance changes in near-infrared region and reveal fast switching from one second to several seconds.