A method for measuring excitation response, applied to an electrical impedance tomography device, wherein the electrical impedance tomography device comprises at least two electrode belts (1, 2) and each electrode belt (1, 2) comprises multiple electrodes (11-116, 21-216), the method comprising the following steps: applying, at the same moment, excitation currents having different frequencies within a designated frequency range to excitation electrode pairs of the at least two electrode belts (1, 2) respectively, and measuring a voltage difference of a measurement electrode pair of each electrode belt (1, 2) at the moment, wherein the excitation electrode pair is selected from multiple electrodes (11-116, 21-216) of the same electrode belt (1, 2), and the measurement electrode pair is selected from electrodes (11-116, 21-216) in the same electrode belt (1, 2) other than the excitation electrode pair; and separating the measured voltage differences of the measurement electrode pairs into multiple sets of voltage differences respectively corresponding to the different frequencies of the excitation currents, and using the multiple sets of voltage differences as electrical impedance tomography data, characterized in that the step of separating the measured voltage differences of the measurement electrode pairs into multiple sets of voltage differences respectively corresponding to the different frequencies of the excitation currents, further comprises the following steps: performing discrete Fourier transform on the voltage differences of the measurement electrode pairs to obtain frequency-domain signals corresponding to the voltage differences; sequentially taking, according to excitation frequencies of different electrode belts (1, 2), a midpoint value of each two adjacent excitation frequencies as a boundary frequency of the frequency-domain signals; separating, according to the boundary frequency, the frequency-domain signals corresponding to the voltage differences; and performing inverse discrete Fourier transform on the separated frequency-domain signals to obtain multiple sets of voltage differences respectively corresponding to the different frequencies. applying, at the same moment, excitation currents having different frequencies within a designated frequency range to excitation electrode pairs of the at least two electrode belts (1, 2) respectively, and measuring a voltage difference of a measurement electrode pair of each electrode belt (1, 2) at the moment, wherein the excitation electrode pair is selected from multiple electrodes (11-116, 21-216) of the same electrode belt (1, 2), and the measurement electrode pair is selected from electrodes (11-116, 21-216) in the same electrode belt (1, 2) other than the excitation electrode pair; and separating the measured voltage differences of the measurement electrode pairs into multiple sets of voltage differences respectively corresponding to the different frequencies of the excitation currents, and using the multiple sets of voltage differences as electrical impedance tomography data, characterized in that the step of separating the measured voltage differences of the measurement electrode pairs into multiple sets of voltage differences respectively corresponding to the different frequencies of the excitation currents, further comprises the following steps: performing discrete Fourier transform on the voltage differences of the measurement electrode pairs to obtain frequency-domain signals corresponding to the voltage differences; sequentially taking, according to excitation frequencies of different electrode belts (1, 2), a midpoint value of each two adjacent excitation frequencies as a boundary frequency of the frequency-domain signals; separating, according to the boundary frequency, the frequency-domain signals corresponding to the voltage differences; and performing inverse discrete Fourier transform on the separated frequency-domain signals to obtain multiple sets of voltage differences respectively corresponding to the different frequencies. performing discrete Fourier transform on the voltage differences of the measurement electrode pairs to obtain frequency-domain signals corresponding to the voltage differences; sequentially taking, according to excitation frequencies of different electrode belts (1, 2), a midpoint value of each two adjacent excitation frequencies as a boundary frequency of the frequency-domain signals; separating, according to the boundary frequency, the frequency-domain signals corresponding to the voltage differences; and performing inverse discrete Fourier transform on the separated frequency-domain signals to obtain multiple sets of voltage differences respectively corresponding to the different frequencies.