A newly developed iron-based multi-component nanocrystalline (Fe_(85.2)Zr_(3.3)Nb_(3.5)B_3Si_3-)Al_1Cu_1 alloy was observed by atomic force microscopy(AFM) at the stages of quenched-state, (annealed-state) for 10,60,600 min to investigate the surface roughness and crystallization. During the observation and analysis, the roughness of amorphous precursor's surface was calculated. The vertical roughness R_V (0.354 nm) and the horizontal one R_H (0.648 nm) were obtained. Meanwhile, the predicting formula of average grain size was given which was according with the (Beck's) formula. In addition, the velocity constant C(32.06) and dynamic exponent (n(0.14)) were drawn out that was much smaller than other nanocrystalline materials symbolizing the slower surface grain growth.