A wide-angle camera for a head-mounted device, includes, but is not limited to, a casing, a biconvex plus lens, and a biconcave minus lens. The biconvex plus lens and the biconcave minus lens are arranged in parallel in the casing and the biconcave minus lens is closer to an object space. The bioconcave minus lens is able to move along an axis of the casing to adjust a distance to the bioconvex plus lens. The focal power of a zooming system of the wide-angle camera is set to be a range from −0.005 to 0.005, an thus the bioconvex plus lens is stationary in the camera, and a movement of the bioconcave minus lens enables the camera to be suitable for the crowds of 500 degree nearsightedness to 500 degree farsightedness.