The purification efficiency of trickling biofilter with waste gas subsection-inlet is numerically computed based on the capillary model. The studied trickling biofilters involve the one with several subsection-inlets but only one exit and another with several subsection-inlets and exits. The purification efficiency of the trickling biofilter with several subsection-inlets and one exit is lower than the traditional trickling biofilter with one inlet and exit under the same operational conditions. As the number of subsection-inlet increases, the purification efficiency decreases. For the trickling biofilter with several subsection-inlets and one exit, the number of subsection-inlet has very little influence on the purification efficiency that is very close to the purification efficiency of the trickling biofilter with one inlet and exit.