Large scale helium liquefaction/refrigeration plant plays a vital role in the advanced large equipment such as fusion reactors and accelerators. A new helium liquefaction cycle with double stage compressor is proposed in this paper, which is different from the Collins cycle. The helium gas from the compressor is divided into two parts. The medium-pressure helium gas as one part flows through the heat exchangers and is liquefied by throtting in the value. The other part, high-pressure helium gas flows into the turbine for adiabatic expansion with decrease of its temperature and pressure. Both high-temperature helium gas streams become low-temperature and low-pressure. In this paper, the new cycle is parametrically analyzed to demonstrate the effect of each parameter on the performance of the cycle. The results of the refrigerating capacity and liquefaction capacity are obtained in different working conditions. Energy analysis, which is an effective way to analyze thermodynamic cycles, is performed on the liquefaction process and the result is significant for the appropriate design of helium liquefaction system.