根据税法的有关规定,非正常损失是指纳税人在生产经营过程中正常损耗外的损失,具体包括因水灾、旱灾、火灾、地震等自然灾害而造成的货物损失;因管理不善造成货物被盗、残损、霉烂变质损失;因超定额损耗等因素形成的其它非正常损失。非正常损失货物的进项税额不得抵扣销项税额。因此企业发生非正常损失时,应采用一定的方法计算其不得抵扣的进项税额。 According to the relevant provisions of the tax law, abnormal losses refer to the normal loss of taxpayers in the course of production and operation, including the loss of goods caused by floods, droughts, fires, earthquakes and other natural disasters; theft of goods caused by poor management Loss, damage, mildew, spoilage; other abnormal losses due to over-quota losses, etc. The amount of input tax for abnormally damaged goods cannot be offset against the output tax amount. Therefore, when an enterprise suffers an abnormal loss, it shall use a certain method to calculate its input tax amount that cannot be deducted.