Abstract: Presented a typical heat sink in a space simulator with heat transfer model.(Compared) to other fin-structure radiators,heat sink for space simulator is characterized by looking into the enhancement of its thermal uniformity.Thus a detailed parametric study was performed by varying heat sink dimensions(fin length,fin thickness,and liquid nitrogen pipe radius) and(surrounding) conditions(liquid nitrogen velocity).It was found that thermal uniformity increased the most with the decrease of fin length,increase of fin thickness,and increase of liquid nitrogen pipe radius as well as the liquid nitrogen flowing velocity.At last,optimized heat sink parameter ranges were offered with help of numerical analysis results after(taking) some real design factors into consideration.