The invention relates to the three-dimensional model conversion technology and aims at solving the problems that in the prior art, when an overall characteristic curve of a model turbine is converted into an operating overall characteristic curve of a prototype turbine, an auxiliary line needs to be drawn, the workload is large, man-made influence factors are more, and working efficiency and drawing precision are low. According to a method for generating the operating overall characteristic curve of the prototype turbine, according to the overall characteristic curve of the model turbine, coordinates of points on equivalent efficiency lines of the prototype turbine, coordinates of points on equivalent output lines of the prototype turbine, coordinates of points on equivalent draft height lines of the prototype turbine, coordinates of points on equivalent guide vane opening lines of the prototype turbine and the like are calculated through computer software, on the basis, equivalent efficiency lines, equivalent output lines, equivalent draft height lines, equivalent guide vane opening lines, output limiting lines and the like of prototype turbine are drawn on H-P and Q-P plane coordinate graphs respectively, and then operating region division of the prototype turbine is further realized. The method is suitable for converting the overall characteristic curve of the model turbine the operating overall characteristic curve of the prototype turbine.