Aiming at that the traditional Greitzer blower model is not appropriate for the object, an improved model of pipeline and outlet pressure is present in which the motor speed is variable. Compared with the original Greitzer model, the improved model considers the inevitable bending pipe in practical applications and the local pressure loss of the elbow. Moreover, the pressure loss along the pipeline which is neglected in the original model is also included. Therefore, the export pressure is more accurately calculated by the improved model. The validity and accuracy of the improved model are verified by comparing the experimental data with the model theory results. Furthermore, the relative errors in the medium and high-pressure output stage are within ±3% and ±1%, respectively. In addition, the comparison between the improved model and the model without the pipeline pressure loss is also made. The result shows that the accuracy of the improved model has been improved by ±1% both in the medium and high-pressure output stage.