1. A contactless detection method with noise elimination for information of physiological and physical activities, comprising steps of: providing an image sensor for capturing an image of a human body portion to produce a primitive image; defining a feature point of the human body portion from the primitive image; tracing an information for coordinate movement of the feature point to create a displacement signal; capturing a complexion fluctuation of the human body portion to form a pending physiological signal including a noise; inputting the displacement signal and the pending physiological signal into an adaptive filter to eliminate the noise in the pending physiological signal for generating an ideal physiological signal; performing a first peak/trough detection on the ideal physiological signal to calculate out an physiological information; and performing a second peak/trough detection on the displacement signal to calculate out an information of physical activity.