The large evanescent field of optical micro-nano fiber (OMF) has enormous prospect in optical fiber sensing. In this paper, the factors that affect OMFs profile during taping process are analyzed. Accurate OMFs profile can be tapered by improved art and choosing proper parameters. Two OMFs is tapered and their profiles coincide well. The relationship between adhered particulates and additional loss of OMF is theoretically simulated, and the corresponding experiments are carried out by using dust in air and 2 μm-in-diameter alumina particulates. The relationship between absorption coefficient of liquid and additional loss of OMF is also calculated, and the absorption coefficient of different kinds of liquids are tested.