Determination method for pre-cutting allowance line of ship plate

The invention relates to the technical field of ships, in particular to a method for determining a pre-cutting allowance line of a ship plate, which comprises the following steps of: drawing an auxiliary line at a position, which is S away from a port of a carrying section, on the carrying section; marking and measuring port line data P1 on the carrying section, marking and measuring port line data P2 on the reference section, and marking and measuring intersecting line data P3 of the mounting positions of the auxiliary line and the carrying end structure of the carrying section; the port line data P1 of the carrying section, the port line data P2 of the reference section and the intersection line data P3 of the auxiliary line are imported into a simulation system, each point in the intersection line data P3 is linearly connected with a point, located on the same section with the point, in the port line data P2, and the length Lx of a connecting straight line is calculated and output; and when the allowance i