1. A method for forming surrounding seamless bird-view image, comprising the steps of: providing a plurality of surrounding images; performing a viewpoint transformation process upon the plural surroundings for transforming the same into a plurality of corresponding bird-view images; identifying an overlapped region from any two adjacent bird-view images; performing a weight calculation process for multiple times so as to obtain an overlapped image from the overlapped regions of any two adjacent bird-view images, as each weight calculation process further comprises the step of: measuring a distance between each pixel in the overlapped region and the boundary of the overlapped region in one of the corresponding two adjacent bird-view image and another distance between the same pixel and the boundary of the overlapped region in another corresponding two adjacent bird-view image; determining a first weighting value for each pixel in the overlapped region of one of the corresponding two adjacent bird-view image while determining a second weighting value for the corresponding pixel of another adjacent bird-view image according to the measured distances of the pixel; and performing a weighted feature calculation on an image feature of the corresponding pixels in the overlapped regions of the two adjacent bird-view images by the use of the first weighting value and the second weighting value so as to obtain an overlapped feature for the corresponding pixel; and combining the plural overlapped images and the portions of the plural transformed bird-view images that are not overlapped into a surrounding seamless bird-view image.