An exhaust postprocessing component comprises an exhaust pipe, a first support installed on the exhaust pipe, a common rail installed on the first support, an inlet pipeline and an outlet pipeline that are connected to the common rail, a sensor, and a bundle that is connected to the sensor. The common rail comprises a shell and a pressure detection apparatus and a pressure adjustment apparatus that are installed on the shell. The shell comprises an inlet passage and an outlet passage. The pressure detection apparatus is connected to the inlet passage. The pressure adjustment apparatus is connected between the inlet passage and the outlet passage, so as to connect or disconnect the inlet passage and the outlet passage. The engine exhaust postprocessing component further comprises a second support. The bundle, the inlet pipeline, and the outlet pipeline are all gathered at the second support. In this way, the exhaust postprocessing component is easy to be installed with another component.