A flow-calculating scheme applied to an electromagnetic flowmeter, the electromagnetic flowmeter comprising a calculating unit, a measuring unit and a memory unit, the flow-calculating scheme comprising: a) measuring, by the measuring unit, a plurality of induced electromotive forces generated by a fluid in a tube to obtain a plurality of measured signals represented by a measured reference voltage of constant amplitude or of linear time dependence and a series of pulse signals (102, 103) superimposed on the measured reference voltage; b) storing the measured signals by the memory unit; and c) sampling, by the calculating unit, the measured signals stored in the memory unit in a specific interval to perform a flow calculation of the fluid, wherein at least one first-direction pulse signal and at least two second-direction pulse signals are in the specific interval, and the at least two second-direction pulse signals are before the at least one first-direction pulse signal and after the at least one first-direction pulse signal respectively; characterized in that the flow calculation comprises: d) assigning the at least one first-direction pulse signal as a reference signal by the calculating unit; e) defining the at least one second-direction pulse signal before the reference signal as a first signal group by the calculating unit; f) defining the at least one second-direction pulse signal after the reference signal as a second signal group by the calculating unit; g) utilizing, by the calculating unit, the reference signal and a first feature value of the first signal group to obtain a first difference value; h) utilizing, by the calculating unit, the reference signal and a second feature value of the second signal group to obtain a second difference value; i) calculating, by the calculating unit, the first difference value and the second difference value to obtain a result weighting value; and j) utilizing, by the calculating unit, the result weighting value to obtain a flow measurement result of the fluid; wherein the at least one first-direction pulse signal is of an amplitude higher than the measured reference voltage; and the at least one second-direction pulse signal is of an amplitude lower than the measured reference voltage; wherein in the step c), the calculating unit utilizes a conformal mapping to rotate the measured signals by a predetermined angle and then performs the flow calculation; wherein in the step d), the calculating unit defines the reference signal as a present voltage signal, and defines that a present voltage signal peak value is a maximum of the present voltage signal or a minimum of the present voltage signal; in the step e), the calculating unit defines the first signal group as a previous-y-time voltage signal, and defines the y as a positive integer greater than zero; and after the step i), the flow calculation further comprises: i1) defining a p value as a predetermined voltage value by the calculating unit; and i2) calculating, by the calculating unit: a present flow signal = {(the present voltage signal peak value - an average value of the p value of the previous-y-time voltage signal) + (the present voltage signal peak value - the p value of the present voltage signal)}/2. a) measuring, by the measuring unit, a plurality of induced electromotive forces generated by a fluid in a tube to obtain a plurality of measured signals represented by a measured reference voltage of constant amplitude or of linear time dependence and a series of pulse signals (102, 103) superimposed on the measured reference voltage; b) storing the measured signals by the memory unit; and c) sampling, by the calculating unit, the measured signals stored in the memory unit in a specific interval to perform a flow calculation of the fluid, d) assigning the at least one first-direction pulse signal as a reference signal by the calculating unit; e) defining the at least one second-direction pulse signal before the reference signal as a first signal group by the calculating unit; f) defining the at least one second-direction pulse signal after the reference signal as a second signal group by the calculating unit; g) utilizing, by the calculating unit, the reference signal and a first feature value of the first signal group to obtain a first difference value; h) utilizing, by the calculating unit, the reference signal and a second feature value of the second signal group to obtain a second difference value; i) calculating, by the calculating unit, the first difference value and the second difference value to obtain a result weighting value; and j) utilizing, by the calculating unit, the result weighting value to obtain a flow measurement result of the fluid; i1) defining a p value as a predetermined voltage value by the calculating unit; and i2) calculating, by the calculating unit: a present flow signal = {(the present voltage signal peak value - an average value of the p value of the previous-y-time voltage signal) + (the present voltage signal peak value - the p value of the present voltage signal)}/2.