In this study, we reported a plasma method to generate the cold pulsed glow discharge for large-area surface modifications of various polymers, such as polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polytetrafluoroethylene (PTFE). The cold plasmas consisting of pulsed and glow-like breakdowns with peak widths of several microseconds may efficiently prevent the heat-sensitive materials from being damaged and greatly improve the surface properties of treated polymers. Analysis indicates that discharge parameters, such as the discharge pressure and gas compositions, may significantly influence the density of radicals or ions generated near the polymer surface, and their energy, which in turn determine the surface properties of treated polymers, such as surface chemical compositions and hydrophobicity. The reaction processes of activated species, such as radicals and energetic ions at the surfaces of treated polymers, are discussed based on the obtained experimental results. Compared to many other plasma techniques formed at high pressure or with a long discharge distance, the low-pressure plasmas generated through small gas spacing from this design may result in the efficient and frequent collisions between the polymer surface and activated species, thus demonstrating an efficient usage of electric energy and feed gas.