The present invention discloses a diagnosis method of a natural gas measurement system. The method includes the following steps that: the historical natural gas measurement data of each preset time point of each of N preset time periods are acquired; a maximum value and a minimum value of N historical natural gas measurement data corresponding to each preset time point are acquired; the current natural gas measurement data of each preset time point of the preset time periods are acquired, whether the current natural gas measurement data of each preset time point are located between the maximumvalue and minimum value of the historical natural gas measurement data corresponding to the preset time point is judged, and the ratio of the number of time points of which the current natural gas measurement data are located between the maximum values and minimum values of the historical natural gas measurement data to the total number of the preset time points in the preset time periods is calculated; if the ratio is larger than or equal to a preset value, the natural gas measurement system works normally; if the ratio is smaller than the preset value, an abnormality exits on the natural gas measurement system. With the method provided by the invention adopted, whether the natural gas measurement system malfunctions can be effectively judged.