Abstract: Solution and quenching heat treatments are generally carried out in a roller hearth furnace for large-scale thick aluminum alloy plates. However, the asymmetric or uneven spray water flow rate is inevitable under industrial production conditions, which leads to an asymmetric residual stress distribution. The spray quenching treatment was conducted on self-designed spray equipment, and the residual stress along the thickness direction was measured by a layer removal method based on deflections. Under the asymmetric spray quenching condition, the subsurface stress of the high-flow rate surface was lower than that of the low-flow rate surface, and the difference between the two subsurface stresses increased with the increase in the difference in water flow rates. The subsurface stress underneath the surface with a water flow rate of 0.60 m³/h was 15.38 MPa less than that of 0.15 m³/h. The simulated residual stress by finite element (FE) method of the high heat transfer coefficient (HTC) surface was less than that of the low HTC surface, which is consistent with the experimental results. The FE model can be used to analyze the strain and stress evolution and predict the quenched stress magnitude and distribution.