A multi-carriage dual-spindle symmetrical grinding processing center, comprising a front base, a back base, a work table, a first upright post, a second upright post, a first carriage, a second carriage, a third right carriage, a first grinding head, and a second grinding head; wherein: the first carriage is slidingly attached to and slidable in a back and forth motion on the front base, the work table is slidingly attached to and movable in a left and right motion on the first carriage; the second carriage is installed between the first upright post and the second upright post, and the first upright post and the second upright post are positioned symmetrically in a gantry form on the back base; the third right carriage is connected to the outer side of the second upright post and can slide up and down along the second upright post, and a right slider is attached to and slidable in a back and front motion on the third right carriage; the first grinding head, positioned horizontally and extended forwardly over the work table, is slidingly attached to the front end of the second carriage, and is slidable in a up and down motion driven by the second carriage and slidable in a back and front motion along the second carriage; and the second grinding head, positioned vertically, is slidingly attached to the front end of the right slider on the third right carriage, and can be automatically rotated; the second grinding head can be automatically rotated in 120 degrees; the grinding processing center being characterized in that a rotary table is installed on the work table; the second grinding head is equipped with an automatic tool changing device which comprises a tool magazine and a mechanical arm; a third left carriage is connected to the outer side of the first upright post and can slide up and down along the first upright post, and a left slider is attached to and slidable in a back and front motion on the third left carriage; a grinding wheel profile dresser is installed on the second carriage and on the front end of the left slider on the third left carriage, and the grinding wheel profile dresser is positioned with an elevation angle for the first grinding head, wherein the grinding wheel profile dresser comprises a grinding wheel dressing kit and a laser detection device so as to being able to perform on-line inspection and wheel dressing. the first carriage is slidingly attached to and slidable in a back and forth motion on the front base, the work table is slidingly attached to and movable in a left and right motion on the first carriage; the second carriage is installed between the first upright post and the second upright post, and the first upright post and the second upright post are positioned symmetrically in a gantry form on the back base; the third right carriage is connected to the outer side of the second upright post and can slide up and down along the second upright post, and a right slider is attached to and slidable in a back and front motion on the third right carriage; the first grinding head, positioned horizontally and extended forwardly over the work table, is slidingly attached to the front end of the second carriage, and is slidable in a up and down motion driven by the second carriage and slidable in a back and front motion along the second carriage; and the second grinding head, positioned vertically, is slidingly attached to the front end of the right slider on the third right carriage, and can be automatically rotated;