The invention discloses a semisteel smelting and slag remaining method under the dry dedusting conduction, belonging to the technical field of steel smelting. According to the invention, semisteel smelting is continuously carried out in a decarburization furnace; when the slag remaining operation condition is met, the slag is splashed and then remained; after the slag is remained, the next furnace time is started; after iron is blended, smelting is started; on the basis of meeting the normal production process, a reasonable oxygen supplying scheme, a slag-making scheme and the like are determined through optimizing blowing gun position and optimizing overskirt operation; and blowing is well controlled, the blowing process is controlled to well melt slag, splashing is not generated, dephosphorization rate is good, the final hit rate is high, and alarming and gunning and explosive decompression are not generated. Through application of the method, the amount of slagging agent is reduced, production cost is reduced, and social, economic and environmental benefits are obvious.