A mixing apparatus for exhaust gas postprocessing, comprising a housing, a mixing assembly located in the housing, and a partition, wherein the partition divides the housing into a first chamber in communication with an inlet and a second chamber in communication with an outlet. The mixing assembly comprises an inner tube, a dispensing body, an outer tube and an end cap; the inner tube is provided with a first tubular body located in the first chamber and a second tubular body extending into the second chamber; a wall of the first tubular body is provided with several rotating flow sheets, and a wall of the second tubular body is provided with several first perforations through which airflow passes; the dispensing body is provided with several through holes through which airflow passes; the outer tube is located on the periphery of the second tubular body, and a wall of the outer tube is provided with several second perforations through which airflow passes; the end cap is located at the bottom of the outer tube and is used to force airflow to reverse. Such an arrangement increases distance and time of urea evaporation, and improves uniformity of airflow mixing.