Abstract: A new data transforming method of D/F(digital to frequency conversion) was adopted to export frequency in the novel digital Coriolis mass flowermeter. The frequency output was completed by the crystal and the FPGA(field programmable gate arrays) together with the DSP(digital signal processing). The influence of V/F(voltage to frequency conversion method) in the traditional analog Coriolis mass flowmeter was avoided, for example, the conversion precision was not high, temperature excursion and the circuits were more complex. And the frequency output was not whole period because of the frequency update, which influenced the frequency output result. The experimental results show that the transforming method of digital to frequency conversion has high conversion precision and realizes the whole period frequency output. In addition, it also has not the temperature excursion of the voltage to frequency conversion method. The circuits are simple and seamless to connect with digital circuit. Thus the method is well worthy applying in digital system.