Telescopic filter capable of being maintained on line

The invention discloses a telescopic filter capable of being maintained on line. The telescopic filter comprises a filter body and a filter screen assembly detachably connected to the interior of the filter body, an opening allowing the filter screen assembly to penetrate out is formed in the top of the filter body, and a top cover matched with the opening is detachably connected to the opening. A desilting assembly for removing impurities in the filter body is arranged at the bottom of the filter body; and a water inlet interface of the filter body is hermetically connected with a telescopic structure capable of stretching along the water flow direction. The device is simple in structure and reasonable in design, the filter screen is very convenient to mount and dismount, and desilting and overhauling are facilitated; meanwhile, the defect that the sealing performance of the joint of the pipeline and the filter is influenced by pipeline deflection is overcome. 本发明公开了一种可在线维护的伸缩过滤器，包括过滤器本体和可拆卸连接于所述过滤器本体内部的滤网组件