The invention relates to a high-precision multi-transformation-ratio standard current transformer working for a long time under 150% rated current, and belongs to the technical field of electric energy metering. The transformer comprises a shell, a primary winding, a secondary winding, an air passage, an insulating film, an iron core, an error compensation unit, a power supply and control module, a man-machine interaction unit, a fan, a self-locking universal wheel and a wiring terminal strip. By applying heat dissipation measures, error compensation measures and the like, the measurement accuracy and stability of the standard current transformer working for one hour for a long time under the condition of 150% rated current are guaranteed, meanwhile, the measurement accuracy and stability under the condition of 1-120% rated current are met, the technical support is provided for overload and error tests of the current transformer, and management of work such as current transformer network access detection, arrival acceptance check, operation quality, production and manufacturing and the like can be enhanced.