Multi-core filters have a wide range of applications and are suitable for various working conditions. The filtercartridge adopts a folded membrane filtercartridge, and the interface is distinguished by 222 and 226 interfaces. The precision can be as fine as 0.22 microns. The number of filter cartridges can be 3 cores, 5 cores, 7 cores, 9 cores, and so on. The filtercartridge can be a melt-blown filtercartridge, a wire wound filtercartridge, a folded film filtercartridge, a high flow filtercartridge, a metal filtercartridge, and so on.