本文用沉浸法研究小样品沉浸入过冷液氮的沸腾传热特性。实验发现，沉浸样品的直径减少、液氮过冷度增大，均导致沸腾的热流密度急剧向右上方移动。当小直径足够小，过冷度足够大时，稳定膜态沸腾段消失了，“Ｍ”形的沸腾曲线变为“Λ”形。 In this paper, the immersion method was used to study the boiling heat transfer characteristics of submerged sub-cooled liquid nitrogen. The experimental results show that the diameter of immersed sample decreases and the subcooling degree of liquid nitrogen increases, which leads to the rapid and upward heat flux of boiling. When the small diameter is small enough and the supercooling degree is large enough, the stable film boiling phase disappears, and the “M” boiling curve becomes “Λ”.