The motion equation of boom system of pump truck carrying concrete flow is set up based on the coupled vibration theory of cantilevered pipe and the finite element theory. Dynamic stress history of boom system with parameters of dip angle α=0°is simulated combining MATLAB simulation analyses with ANSYS finite element model. The feasibility of this method is verified through field experiment. Stress histories are simulated by adjusting parameter of dip angle as follows: α=20°,52°and 80°.Great stress points are painted on the Goodman Fatigue Limit Diagram measured by experiment. And then fatigue strength assessment of boom system is done. The research method can be used for the design calculation of similar products.