A box-type generator driven by an engine, comprising a box-type soundproof hood assembly (3) enclosing the whole generator, a controller (2), an oil tank (19), a front and a back fans (13, 14), air ducts (11, 12), a permanent magnetic generator (4), an engine (5), a double-cavity type muffler assembly (6) and the like. With the novel designs such as forward fans air inlet (17) and controller arrangement, dual cooling air ducts and double muffler structure, and the integrated overall layout of the control system, the box-type generator ensures a generator cooling system to sequentially cool down heating components in a temperature ascending order, thus effectively reducing the system noise of a generator assembly, and facilitating the use, installation and maintenance of the generator.