An image capture device and a dustproofing method thereof. The image capture device comprises a switch module, optical-component adaptor module, optical-component adaptor detecting module, mask module, power detecting module and controlling module. The switch module switches the image capture device on or off and produces an on signal or off signal correspondingly. The optical-component adaptor detecting module detects whether a removable optical-component is connected with the optical-component adaptor module and produces a detecting signal. The power detecting module measures the residual power in the image capture device and produces a residual power signal. The controlling module, according to the on signal, off signal, detecting signal and the residual power signal controls the mask module to shield or un-shield the photosensor. Therefore, when the image capture device is powered off or during replacement of removable optical-components, the mask module shields the photosensor to render it dustproof.