As a core of selective catalytic reduction (SCR) De-NOx device, catalysts play a key role in the operation of De-NOx device. The catalysts are easily blocked because of the high and unstable ash in flue gas in domestic coal-fired units. The harmful substance in flue gas, such as arsenic, alkaline, etc., could lead to the deactivation of catalysts due to the chemical poisoning. These problems could be well solved when plate-type catalysts were used due to their special structure (big opening ratio) and processing technology (using flexible stainless steel meshes as carrier and MoO3 as promoter). With catalyst performance stability as the standard, the advantages of plate-type catalysts in coal-fired units from the aspects of blocking, coverage, abrasion, and chemical poisoning are discussed in this paper.