Abstract: The working environment of concrete pump trucks is complex and variable, and their operating postures change frequently. As a critical component of the pump truck, the arm frame system requires close attention to its vibration response and the avoidance of resonance during operation. Meanwhile, the delivery pipe mounted on the arm frame is subjected to unstable fluid impacts and structural loads while pumping, making its stress distribution and structural strength equally essential. In this study, ANSYS is used to perform a modal analysis of the arm frame, obtaining its first six mode shapes. On this basis, a fluid-structure interaction finite element model of the arm frame delivery pipe is established to analyze the concrete delivery pipe, focusing on the stress distribution characteristics and the locations of dangerous points under five typical working conditions. The research results can provide important references for anti-resonance design of pump truck arm frames and for assessing their fatigue safety.