The invention discloses a welding method of an exhaust manifold and a connection component. The welding method of the exhaust manifold and the connection component comprises the following steps that firstly, a base is horizontally placed, a flange to be welded is placed on the side face of a side platform, the edge of the flange is clamped through limiting plates, and the flange is fixed to the side platform through fixing rings; secondly, one side of the exhaust manifold to be welded is placed between fixing blocks, a second drive mechanism is moved along a second sliding groove, the height of the side platform is adjusted at the same time, and the welding portion of the flange and the welding portion of the exhaust manifold are made to be located at the same height; and thirdly, the flange is rotated around a second drive shaft, it is guaranteed that the welding face of the flange is in contact with the welding face of the exhaust manifold, the exhaust manifold is kept fixed, movablerods are sequentially adjusted to enable clamp plates to fix the exhaust manifold, when the exhaust manifold is fixed, the heights of the clamp plates are adjusted through first drive mechanisms, meanwhile the intervals between the clamp plates are adjusted through first sliding grooves, the clamping force on the exhaust manifold is increased, and when the exhaust manifold is well fixed, the exhaust manifold and the flange are welded.