A detection device and a detection method for a light emitting element are provided. The detection device includes a piezoelectricity sensor and a light sensing circuit. The piezoelectricity sensor includes a first piezoelectricity element, wherein the first piezoelectricity element is used to contact a first electrode of the light emitting element to cause a first deformation of the first piezoelectricity element. The first piezoelectricity element generates a first voltage based on the first deformation to power the first electrode. A second electrode of the light emitting element is coupled to a reference voltage. The light sensing circuit is used to sense whether the light emitting element powered by the first voltage emits light.