Optical micro/nanofibers (MNFs) taper-drawn from silica fibers possess intriguing optical and mechanical properties. Recently, MNF array or MNFs with identical geometries have been attracting more and more attention, however, current fabrication technique can draw only one MNF at a time, with a low drawing speed (typically 0.1 mm/s) and a complicated process for high-precision control, making it inefficient in fabricating multiple MNFs. Here, we propose a parallel-fabrication approach to simultaneously drawing multiple (up to 20) MNFs with almost identical geometries. For fiber diameter larger than 500 nm, measured optical transmittances of all as-drawn MNFs exceed 96.7% at 1550-nm wavelength, with a diameter deviation within 5%. Our results pave a way towards high-yield fabrication of MNFs that may find applications from MNF-based optical sensors, optical manipulation to fiber-to-chip interconnection.