Abstract: A data acquisition system was built to determine the characters and performance of lower power arcjet thrusters in the ground experiments.Testing principle of working parameters,composition of software and hardware of the system,correlative technical parameters of hardware were depicted in details.Measurement accuracy in working channels were analyzed.Typical testing results were also given.A conclusion can be drawn through the analysis that this data acquisition system can measure working parameters of thrusters accurately,especially obtain the micro mass flow rate and small thrust data,so that the ground experimental status is reflected really.This data acquisition system provides a test platform with reliability for further study on low power arcjet thrusters.