Abstract: The new revised standard of GB 18047-2017 Compressed Natural Gas for Vehicles is explained in detail from the points of view of the technical requirements and the change of test methods, and indicates that the new standard needs to be improved. It has been found that the technical requirements of CNG haven't changed a lot except for total sulphur (in terms of sulphur) which has decreased from 200 mg/m³ to 100 mg/m³. In the aspect of water content/water dew point, it is the first time to use "water mass concentration" instead of "water dew point" to evaluate the water condition in CNG when the environmental temperature is below the reference dividing point. Moreover, the test methods of each technical requirement have been enriched and expanded overwhelmingly, while the arbitration methods are also specified which are almost the same as the old standard.In addition, the lower limit value of superior calorific value does not accord with the actual situation. It is suggested that the standard of superior calorific value should be raised appropriately, and a new detection item"liquid hydrocarbon content/hydrocarbon dew point" should be added to the technical index of compressed natural gas for vehicle use.