In this work, polymethylmethacrylate (PMMA) as a superior mediate for the pressure welding of silver nanowires (Ag NWs) networks as transparent electrodes without any thermal treatment is demonstrated. After a pressing of 200 kg cm−2, not only the sheet resistance but also the surface roughness of the PMMA‐mediated Ag NWs networks decreases from 2.6 kΩ sq−1 to 34.3 Ω sq−1 and from 76.1 to 12.6 nm, respectively. On the other hand, high transparency of an average transmittance in the visible wavelengths of 93.5% together with a low haze value of 2.58% can be achieved. In terms of optoelectronic applications, the promising potential of the PMMA‐mediated pressure‐welded Ag NWs networks used as a transparent electrode in a green organic light‐emitting diode (OLED) device is also demonstrated. In comparison with the OLED based on commercial tin‐doped indium oxide electrode, the increments of power efficiency and external quantum efficiency (EQE) from 80.1 to 85.9 lm w−1 and 19.2% to 19.9% are demonstrated. In addition, the PMMA‐mediated pressure welding succeeds in transferring Ag NWs networks to flexible polyethylene naphthalate and polyimide substrates with the sheet resistance of 42 and 91 Ω sq−1 after 10 000 times of bending, respectively. An efficient room‐temperature pressure welding technique to fabricate the silver nanowires networks/polymethylmethacrylate composite transparent electrode is reported and demonstrated. In comparison with the organic light‐emitting diode based on commercial tin‐doped indium oxide electrode, the increments of power efficiency and external quantum efficiency from 80.1 to 85.9 lm w−1 and 19.2% to 19.9% are demonstrated.