Polyfurans (PFus) are a type of conjugated polymer but have usually been considered to be inherently unstable and poorly processable. In this work, the multi-component cyclopolymerization (MCC) of diisocyanide, dialkylacetylene dicarboxylates, and dialdehyde was developed to prepare modified PFus under mild conditions with catalyst-free one-pot reactions. The approach afforded high molecular weight poly(amine-furan-arylene)s (PAFAs) (M-w up to 76400), which contained 3,4-substituted furan that in situ formed during the polymerization, with good thermal stability and film-processing properties. All the experimental conditions such as molar ratio of monomers, polymerization solvents and temperature, monomer structures, and reactivity were investigated in detail. PAFAs' structures were well characterized by GPC, FTIR, and NMR. One of the PAFAs carrying dimethylbenzene moieties exhibited the characteristics of a black material. Thus, this MCC provides a new method to modify PFus with a variety of functional groups of main and/or side chains.