<p>In order to study the internal pressure fluctuation characteristics of the self-priming pump for the mobile pump truck and its impact on the frame of the pump truck, this paper first conducted a performance test on the self-priming pump for a certain type of mobile pump truck, and then used FLUENT software to calculate the internal flow of the self-priming pump, and analyzed the pressure fluctuation characteristics of the self-priming pump under different flow conditions.In addition, the fluid-structure coupling calculation of the mobile pump truck is carried out, and the displacement and stress distribution characteristics of the mobile pump truck frame under different flow conditions are studied. The results show that the flow field at the inlet of the impeller is stable under the rated flow condition. The frame will produce large displacement and stress under the condition of small flow. With the increase of flow rate, the maximum displacement and maximum stress of the frame gradually decrease.</p>