The invention relates to a saddle-shaped track automation welding method of a collection box large tube socket. The saddle-shaped track automation welding method comprises a first step of acquiring tool parameters, a second step of setting weld pass section parameters and a fit-up gap G, a third step of edge preparation, wherein bevel angles of connecting tubes and female tube intersecting lines at different positions are determined according to a design principle of a uniform section bevel angle, connector portions of the connecting tubes are machined in a cutting mode, a fourth step of inputting the weld pass section parameters, the fit-up gap G, the tool parameters, the bevel angles and related technological parameters of planned adoptive welding technology into a numerical control welding system to calculate pose data of the tail end of a welding gun, and a fifth step of controlling the welding gun to continuously weld in a layer mode by the numerical control welding system according to the pose data. According to the saddle-shaped track automation welding method of the collection box large tube socket, the purpose of automatic, fast and continuous welding of the intersection line track under different pipe diameters is achieved, weld pass is arranged reasonably, connector quality is good, appearance is attractive, arrangement is ordered, and a technique is wide in application range.