The invention discloses a dynamic admittance measurement method for a new energy grid-connected system with a power electronic device. According to the measurement method, a three-phase controlled voltage source is connected in series between a system to be measured and a source measuring system, a disturbance signal generator respectively generates d-axis and q-axis disturbance signals based on asynchronous rotating coordinate system, and the three-phase voltage after the disturbance signals are subjected to dq0/abc transformation is a control voltage of the three-phase controlled voltage source, the system is subjected to disturbance test, the three-phase current flowing through the system to be measured and a dq-axis current component obtained through abc/dq0 transformation are measured and recorded, the d-axis and q-axis disturbance signals and the dq-axis current component after the abc/dq0 transformation are subjected to Fourier analysis, and finally the dynamic admittance of the system to be measured is calculated. According to the measurement method, the disturbance is implemented near the steady-state operating equilibrium point of the system, and the method can be applied to the dynamic admittance measurement of the new energy grid-connected system with active and passive power electronic devices.