Computing method of standard condition sound speed of ultrasonic gas flowmeter

The invention relates to a computing method of a standard condition sound speed of an ultrasonic gas flowmeter. The computing method comprises the steps that working condition gas absolute pressure data p and working condition gas temperature data t of a natural gas in a pipeline are detected and obtained in real time, and meanwhile working condition sound speed data v of the natural gas in the pipeline is obtained by utilizing the ultrasonic gas flowmeter; the standard condition sound speed v of the natural gas is computed and obtained by the ultrasonic gas flowmeter according to the formula v =x t +x p t +x p +x t +z, wherein p is standard condition gas absolute pressure of the natural gas and is 101.325kPa, t is standard condition gas temperature of the natural gas and is 20 DEG C, x and x are constants, x =Az+B, x =A z+B , and A, B, A and B are all constants; and z is a parameter determined by natural gas quality. According to thecomputing method of the standard condition sound speed of the ultrasonic gas