Abstract: Through a two-stage field test involving ash storage and discharge in a coal-fired power plant's ash hopper， the test data and phenomena including stress in the hopper's stiffeners and wall， as well as wall displacement， were analyzed. Field measurements were compared with finite element simulations. Subsequently， the stress state of the ash hopper under both the test load and the full ash load conditions was analyzed using numerical simulations and Design Code of Steel Structures for ESP （JB/T 12127-2015） calculations. The calculation method for the stiffeners was also discussed. The results showed that the maximum dynamic stress at the test point was 147 MPa， and the test load was only 37% of the full ash load. During stable operation of the dust collector， the temperature of the ash hopper was mainly affected by the ambient environment.The thermal stress generated in the structure under temperature effects was non-negligible and should be considered in engineering design. According to the JB/T 12127-2015， the design method for stiffeners exhibited significant errors and did not align with reality. Calculation based on a closed-frame model was demonstrated to be more rational.