A contactless detection method with noise elimination is applied to measuring the information of physiological and physical activities. It includes following steps: sensing a human body to generate an image by an image sensor capturing a physiological signal from the image tracing a feature point of the human body in the image to generate a physical activity signal and calculating information of physical activities covering step count, speed and calories according to the physical activity signal and the physiological signal. In particular, the contactless detection method treats the physiological signal cooperated with the physical activity signal to separate a noise from the physiological signal, so as to generate an ideal physiological signal. Therefore, the physiological information is calculated more accurately according to the ideal physiological signal.
