Based on the demand of working environments below liquid nitrogen temperature for very long wave infrared detectors, a kind of packaging technology for very long wave infrared detectors working at deep low temperature is proposed. Through innovative optimization design of the heat leakage and the chip electrical lead structure of the dewar, the static thermal load of the entire dewar can be controlled to be 0.65 W when the chip operates at a low temperature of 30 K, and the static thermal load at the coldest end position is 0. 3 W.The cooling capacity of the two-stage pulse tube refrigerator that is compatible with the dewar can meet the above thermal load requirements. The packaging test of the detector component is completed. The results show that under the air cooling test condition of the refrigerator expander's hot end, the detector chip can reach the temperature of 35 K, and the outer contour of the dewar is smaller than $130 mmX 180 mm. This technological achievement has promoted the progress of packaging technology for very long wave array infrared detectors operating at deep low temperature.