The mechanism and process of fabricating fiber probe by combining the static and dynamical chemical etching methods is analyzed. In the process of static etching, the height of the meniscus is obtained by the first-order approximate solution of the Young-Laplace equation. The influence of the velocity of the fiber movement on the shape of the fiber probe is analyzed in detail for different time range of the static and dynamic etching. Probes of various structures, such as large cone angle and short taper or multi-taper, can be formed with the combination of the static and dynamical chemical etching methods. The work establish the foundation for fabricating good probe experimentally and extending the application of scanning near field optical microscope (SNOM). The result of above theoretical analysis is the same to the preliminary result obtained on the experiment.