The invention relates to a nondestructive testing method and device for basin type insulator curing degree of high-voltage switch equipment, wherein the nondestructive testing method comprises the following steps: transmitting an ultrasonic pulse to an insulator to be tested; obtaining an ultrasonic reflection signal at the lower bottom surface of the insulator to be tested; carrying out fast Fourier transform on the ultrasonic reflection signal, and calculating a power spectrum of the ultrasonic reflection signal; comparing the peak value of the power spectrum with a relational data base, thus obtaining the curing degree of the insulator to be tested; the relational data base is a corresponding relation of insulator curing degrees obtained by carrying out ultrasonic tests on insulator samples with different curing degrees and the power spectrum of the ultrasonic reflection signal at the lower bottom surface of the insulator. The method disclosed by the invention can effectively realize nondestructive testing on the overall curing degree of the basin type insulator.