A physiological detection system including an image sensor, a conversion unit, a retrieving unit and a processing unit is provided. The image sensor includes a plurality of pixels respectively configured to output a PPG signal. The conversion unit is configured to covert a plurality of PPG signals of a plurality of pixel regions to a plurality of frequency domain signals. The retrieving unit is configured to respectively retrieve a spectral energy of the frequency domain signals corresponding to the pixel regions. The processing unit is configured to construct a 3D energy distribution according to the spectral energies.一種生理偵測系統，包含一影像感測器、一轉換單元、一擷取單元以及一處理單元。該影像感測器包含複數像素分別用以輸出一光體積變化信號。該轉換單元用以將複數像素區域之複數光體積變化信號轉換為複數頻域信號。該擷取單元用以相對該等像素區域分別擷取該等頻域信號之一頻譜能量值。該處理單元用以根據該等頻譜能量值建立一三維能量分佈。
