Imported silver ions are added to the raw materials of GFK antibacterial board, and the GFK antibacterial board with added silver ions effectively kills bacteria. The antibacterial and fungal rate is tested to be over 99.9%. Mildew is caused by moisture or dirt. After testing, the water absorption rate of GFK board is only 0.013%, and there will be no moisture conditions. Its surface is smooth and dense and will not condense dirt. In this way, it can achieve an effective mildew-proof effect. After multiple tests and tests by the national authorized testing center, "Aspergillus niger ATTCC9642, Rope-shaped green plum ATCC11797, Chaetomium globosum ATCC6205, Green Gluecotomyces ATCC9645", the mildew-proof level is 1.