Abstract: In order to make full use of formation pressure, Daniudi Gasfield gas gathering station takes the method of throttling refrigeration in heat exchanger at small pressure difference to dehydrate. The effect of throttling refrigeration dehydration depends on a number of factors, so this paper takes the heater's exchange efficiency and dew point of natural gas as the analysis indexes of throttling refrigeration dehydration effect and carries out experiments on the gas gathering station under different working conditions. The effect of heat exchange area, gas transmission rate, two-step throttle pressure difference and environment temperature on the heat exchange efficiency and dew point of natural gas are analyzed respectively, and the results show that heat exchange efficiency is affected strongly by the heat exchange area and two-step throttle pressure difference while the main factors influencing gas dew point are gas transmission rate and two-step throttle pressure difference. Through adjusting two-step throttle pressure difference, the throttling refrigeration dehydration process can be optimized to enhance dehydration effect.