Mixing is an important and widely used operation in oil refining and right mixing method must be used to meet technical requirements and decrease the cost. Static mixing and dynamic mixing are two frequently-used mixing methods. Static mixer cuts, rotates and recombine fluids running in pipe by using mixing elements and this mixer has such advantages as better dispersion effect, more evenly mixing, more compact structure and lower operation cost than dynamic mixer. Static mixer has been widely used in such processes of petrochemical industry as extraction, desulfurization, oil reconciling and refining and application of static mixer has obtained good process effect and significant economic benefits. Static mixer has broad prospect in petrochemical industry and it is worthy of further study in the future.