The invention provides a high-temperature screen pipe completed well gel-breaking tester which comprises a well wall outer barrel 8 and a screen pipe inner barrel 11 sheathed in the well wall outer barrel, wherein a cavity between the well wall outer barrel and the screen pipe inner barrel is an external circulation cavity 9; the top and the bottom of the well wall outer barrel are respectively provided with an upper cover 19 of the well wall outer barrel and a lower cover 18 of the well wall outer barrel; the top and the bottom of the screen pipe inner barrel are respectively provided with an upper cover 2 of the screen pipe inner barrel and a lower cover 15 of the screen pipe inner barrel; the upper cover 19 of the well wall outer barrel is in close fit with the upper cover 2 of the screen pipe outer barrel, and the upper cover 2 of the screen pipe outer barrel is provided with a quick-change connector 1 communicated with the inner cavity of the screen pipe inner barrel 11; and the side wall of the screen pipe inner barrel 11 is provided with at least one screen 12. The tester of the invention can simulate the underground plugging and filtration conditions of the screen caused by high temperature, high pressure and drilling fluid and the gel-breaking and removing conditions of screen bulkheads caused by the gel-breaking liquid, and can exactly determine the gel-breaking time and determine filtering the velocity of a screen filer cake after determining the gel-breaking.