A　frequency-sweep　experimental　method　for　predicting　noise　of　a　power　capacitor,　　comprises　steps　of　:　　(1)　loading　the　capacitor　with　a　sine　voltage　excitation　with　a　loading　frequency　value　of　½　to　50　times　of　a　power　frequency　in　sequence,　　at　an　increase　of　half　of　the　power　frequency　for　each　time,　　and　measuring　vibration　velocity　at　various　points　on　a　case　of　the　capacitor;　　(2)　under　each　loading　frequency,　　dividing　vibration　velocity　by　a　square　of　each　voltage　applied;　　(3)　calculating　frequency　spectrum　of　a　square　of　the　voltage　of　the　capacitor　according　to　the　voltage　and　a　current　of　the　capacitor;　　(4)　multiplying　the　frequency　spectrum　of　the　square　of　the　voltage　of　the　capacitor　by　the　electromechanical　vibration　frequency　response　function　value　of　the　capacitor　to　obtain　a　vibration　velocity　spectrum　of　the　case　of　the　capacitor;　　(5)　calculating　acoustical　power　of　the　noise.