The superlattice long-wavelength infrared focal plane detectors operate at low-temperatures. The differences in the thermal expansion coefficients among the various material layers of the detectors can lead to deformation and generate thermal stress, which in turn affects the optoelectrical performances of the detector. This study designed two structural modules to achieve the regulation of stress in the superlattice detectors. The changes in dark current and spectral response of InAs/GaSb type II superlattice long-wave infrared focal plane detectors under different stress conditions were explored. The research indicates that within the stress range of -10.7 MPa to 131.9 MPa, the variations in the optoelectrical performance of the detector is small. The detector was subjected to a temperature shock test, and it demonstrated high reliability. Our research results provide guidance for the structural design of InAs/GaSb type II superlattice long-wave infrared focal plane detectors and offer a basis for their performance and reliability assessment.