A vehicle guidance system, comprising: at least two separate reference devices (G1, G2), configured to serve as an orientation reference of a vehicle; a laser scanner device, configured to emit a laser beam and scan a sectorial region with the laser beam so as to measure a distance of a straight connection line for connecting the laser scanner device to any of the at least two separate reference devices, and an angle included between the corresponding straight connection line and a vehicle body of the vehicle, or an angle included between the straight connection lines (L1, L12); a processor, configured to process and store data; wherein the processor determines whether the orientation of the vehicle body in real time is deviating from an initial orientation of the vehicle body at the time when the system starts to operate or not, in accordance with distances of the straight connection lines (L1, L2) from the laser scanner device to a first separate reference device and a second separate reference device of the at least two reference devices respectively, and an angle (α1, α2) included between each of the straight connection lines and the vehicle body, or an angle included between the straight connection lines as sensed by the laser scanner device, wherein the initial orientation of the vehicle body is meant to an orientation of the vehicle body with respect to a straight connection line between the first separate reference device and the second separate reference device, as determined by the vehicle guidance system when the system starts to operate; and wherein the processor is configured: to determine and save the initial orientation of the vehicle body when the system starts to operate, on the basis of the distances of the straight connection lines from the laser scanner device to the first separate reference device and the second separate reference device respectively, and the angle included between each of the straight connection lines and the vehicle body, or the angle included between the straight connection lines measured by the laser scanner device; to establish a rectangular coordinate system with the first separate reference device as an origin of coordinate; and to determine positional coordinates of the second separate reference device and the laser scanner device, wherein an axis of the rectangular coordinate system is parallel to the initial orientation of the vehicle body of the vehicle. at least two separate reference devices (G1, G2), configured to serve as an orientation reference of a vehicle; a laser scanner device, configured to emit a laser beam and scan a sectorial region with the laser beam so as to measure a distance of a straight connection line for connecting the laser scanner device to any of the at least two separate reference devices, and an angle included between the corresponding straight connection line and a vehicle body of the vehicle, or an angle included between the straight connection lines (L1, L12); a processor, configured to process and store data; wherein the processor determines whether the orientation of the vehicle body in real time is deviating from an initial orientation of the vehicle body at the time when the system starts to operate or not, in accordance with distances of the straight connection lines (L1, L2) from the laser scanner device to a first separate reference device and a second separate reference device of the at least two reference devices respectively, and an angle (α1, α2) included between each of the straight connection lines and the vehicle body, or an angle included between the straight connection lines as sensed by the laser scanner device, wherein the initial orientation of the vehicle body is meant to an orientation of the vehicle body with respect to a straight connection line between the first separate reference device and the second separate reference device, as determined by the vehicle guidance system when the system starts to operate; and wherein the processor is configured: to determine and save the initial orientation of the vehicle body when the system starts to operate, on the basis of the distances of the straight connection lines from the laser scanner device to the first separate reference device and the second separate reference device respectively, and the angle included between each of the straight connection lines and the vehicle body, or the angle included between the straight connection lines measured by the laser scanner device; to establish a rectangular coordinate system with the first separate reference device as an origin of coordinate; and to determine positional coordinates of the second separate reference device and the laser scanner device, wherein an axis of the rectangular coordinate system is parallel to the initial orientation of the vehicle body of the vehicle. to determine and save the initial orientation of the vehicle body when the system starts to operate, on the basis of the distances of the straight connection lines from the laser scanner device to the first separate reference device and the second separate reference device respectively, and the angle included between each of the straight connection lines and the vehicle body, or the angle included between the straight connection lines measured by the laser scanner device; to establish a rectangular coordinate system with the first separate reference device as an origin of coordinate; and to determine positional coordinates of the second separate reference device and the laser scanner device, wherein an axis of the rectangular coordinate system is parallel to the initial orientation of the vehicle body of the vehicle.