Abstract: In order to further analyze the stability of the Lvquan reservoir project arch dam, the 3-D 8-node finite element program is used to analyze the stress deformation law under five working conditions:normal pool level+temperature drop, design flood level+temperature rise, fixed pool level+temperature drop, normal pool level+temperature rise, empty reservoir+temperature drop. The calculation shows that the distribution of stress and displacement is reasonable, which conforms to the general law of stress and deformation of arch dam and meets the design requirements.