Polysulfonamide (PSA) is one of the functional materials with excellent heat and flame resistance properties, which can be potentially utilized in aerospace field and other civil fields. This work presents a feasible method for the preparation and characterization of the electrospun polysulfonamide fibers at nanoscale. The micro-surface morphology and micro-structure of the manufactured polysulfonamide fibers were characterized using the scanning electron microscope. The effects of electrospinning parameters on fibers' micro-surface morphology and properties were investigated accordingly. It was found that high solution concentration favors the formation of smooth fibers and the low solution concentration leads to the formation of beaded fibers or beads. Small diameter fibers can be spun by increasing applied voltage. A considerable number of thin fibers with diameters <100 nm can be spun with the setting of 12 wt% concentration, 28 kV applied voltage and 15 cm tip-target distance. The crystallinity of the polysulfonamide fibers was measured by X-ray diffraction and its thermal property was investigated based on the thermogravimetric analysis. The experimental data show that the crystallinity and thermal behavior of polysulfonamide fibers can be influenced by the electrospinning parameters, including the solution concentration, applied voltage and tip-target distance, while the applied voltage has no significant effects on the crystallinity of fibers.