The invention provides a method of direct and rapid machining of rotational molding by lasher and belongs to the field of operation technique. The method of direct and rapid machining of rotational molding by laser in the prior art comprises the steps of A, mold designing, B, module processing, namely input of the data of a module after the module being sliced to a lens rapid make-up machine and technological parameter setting to the lens rapid make-up machine, operation of the lens rapid make-up machine till accomplishment of a module corresponding to input data, C, repetition of the step B till all the modules are accomplished, D, polishing treatment, namely polishing treatment of the molding surface of each module, and E, assembly, namely the assembly of each module according to designed mould assembly drawing. The method of direct and rapid machining of rotational molding by laser mainly comprises the steps of data establishment, module process, polishing and assembly, therefore the few processing steps are needed, and each process is easy to carry out, and thus the method for direct and rapid machining of rotational molding by laser has the advantage of simple forming process.