Abstract: This article briefly describes the work principle and the structure characteristic of apellet injector in Hefei,and its experiment of CH₄ pellet produced and firied under liquid nitrogen freez-ing.The result shows that this injector can produce Φ1 mm×1 mm CH₄ pellet with avelocity of 450 m/s,with good repetition and integrity, and with divergence angle less than ±0.3.