A method for manufacturing a vehicle underbody (301; 407; 408; 607), the method comprising: determining dimensions for the vehicle underbody (301; 407; 408; 607), the dimensions for the vehicle underbody including a length and a width; determining dimensions for at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604), wherein the dimensions for the at least two underbody panels s are determined based on the dimensions for the vehicle underbody (301; 407; 408; 607); selecting the at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604); putting the at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604) in a stamping die for stamping to form concave parts and convex parts on the at least two underbody panels; and welding the stamped at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604) to form the vehicle underbody (301; 407; 408; 607) which is spliced by the at least two underbody panels in the length direction and/or the width direction, so as to make the vehicle underbody (301; 407; 408; 607) reach the determined length and width, characterized in that the determined dimensions of each underbody panel in the at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604) is smaller than or equal to that of the largest underbody panel capable of being stamped by the stamping die; and the determined length and width of the vehicle underbody (301; 407; 408; 607) is larger than or equal to that of the largest underbody panel capable of being stamped by the stamping die, the determined length of the vehicle underbody (301; 407; 408; 607) is larger than the length of the largest underbody panel capable of being stamped by the stamping die; or that the determined width of the vehicle underbody (301; 407; 408; 607) is larger than the width of the largest underbody panel capable of being stamped by the stamping die; selecting the two underbody panels includes cutting a plate material along the length direction to form each of the two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604); and the stamped two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604) are welded along the width direction to splice the vehicle underbody (301; 407; 408; 607). determining dimensions for the vehicle underbody (301; 407; 408; 607), the dimensions for the vehicle underbody including a length and a width; determining dimensions for at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604), wherein the dimensions for the at least two underbody panels s are determined based on the dimensions for the vehicle underbody (301; 407; 408; 607); selecting the at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604); putting the at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604) in a stamping die for stamping to form concave parts and convex parts on the at least two underbody panels; and welding the stamped at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604) to form the vehicle underbody (301; 407; 408; 607) which is spliced by the at least two underbody panels in the length direction and/or the width direction, so as to make the vehicle underbody (301; 407; 408; 607) reach the determined length and width, characterized in that the determined dimensions of each underbody panel in the at least two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604) is smaller than or equal to that of the largest underbody panel capable of being stamped by the stamping die; and the determined length and width of the vehicle underbody (301; 407; 408; 607) is larger than or equal to that of the largest underbody panel capable of being stamped by the stamping die, the determined length of the vehicle underbody (301; 407; 408; 607) is larger than the length of the largest underbody panel capable of being stamped by the stamping die; or that the determined width of the vehicle underbody (301; 407; 408; 607) is larger than the width of the largest underbody panel capable of being stamped by the stamping die; selecting the two underbody panels includes cutting a plate material along the length direction to form each of the two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604); and the stamped two underbody panels (201, 202; 401, 402; 404, 405; 601, 602, 603, 604) are welded along the width direction to splice the vehicle underbody (301; 407; 408; 607).