Abstract: The present disclosure provides a detection system for acquiring the SPR angle, including a modulatable SPR sensor to be detected; an incident light source apparatus; a photoelectric detector; a narrowband filter system; a modulated signal source for generating an alternating current signal that is used to modulate said modulatable SPR sensor; and a data processing system for recording the corresponding relationship between the incident angle and the intensity of the filtered reflected light and further obtaining the resonance angle of said modulatable SPR sensor. The present disclosure also provides a corresponding detection method for acquiring the SPR angle.