Through the EEG test to find out the interface affected by emotion in operation event and the cause, it will provide a scientific basis for interactive prototype design. On the basis of Lange two-dimensional emotion classification model, test subjects' emotional EEG signals when operating interaction prototypes, extract the EEG power of alpha wave in forehead area, after eliminate EEG artifact and fast Fourier transform processing, the EEG power spectrum and different frequencies of EEG power value can be taken as the index of degree of pleasure. We find that the reason of emotional arousal is the understandability, attractiveness and operation steps of the task.