The invention provides a method and system for recognition of a GIS ultrahigh frequency partial discharge signal. The method for recognition of the GIS ultrahigh frequency partial discharge signal comprises the following steps of (1) carrying out preprocessing on the GIS ultrahigh frequency partial discharge signal to obtain a three-dimensional spectrogram, (2) carrying out projection on the three-dimensional spectrogram to form a two-dimensional spectrogram, respectively extracting discharge characteristic parameters which describe shape difference of the two-dimensional spectrogram, and discharge characteristic parameters which describe difference between a positive semi-circle outline and a negative semi-circle outline of the two-dimensional spectrogram to obtain a sample to be detected, and (3) carrying out defect recognition on the sample to be detected according to an ABC-BP model which is built in advance. The method for recognition of the GIS ultrahigh frequency partial discharge signal can carry out rapid convergence to obtain the global optimum, and improves efficiency and accuracy of fault recognition of GIS partial discharge.