In this Letter, a low-cost refractive convex microlens array device based on infrared a polymer is fabricated by a nanoimprinting technique. The device integrates more than 4000 microlenslets within a footprint of 10 mm×10 mm. The surface quality, spectral transmittance, imaging resolution, and surface damage threshold of the device have been fully characterized. The IR imaging and parallel laser inscription experiments confirm the remarkable optical performance of the fabricated device. Owing to the merits of high optical quality, low fluence lose, and simple fabrication, this device is promising in cutting-edge IR applications, such as IR imaging, laser fabrication, and so on.