American artist Chuck Close is famous for his extremely large pixel portrait paintings based on photos with various geometric grids. This type of portrait painting provides people with a new way of viewing — viewing the abstract nearby and the concrete afar. And as the bridge between the abstract and the concrete, it is the grid of pixels with various styles. Based on this, this article uses Close's portrait paintings from 1970 to 1999 to try to analyze his intention to create with photos and the evolvement of the style of pixel portrait paintings, as well as the way he uses photography to express the new vitality of portrait paintings, thereby reflecting the symbiotic relationship between photography and painting.