The application discloses a secondary ink cartridge overflow alarm device and method and ink jet printing system. The secondary ink cartridge overflow alarm device comprises an ink pipe, a liquid detection unit and an alarm unit, wherein the ink pipe is connected from the bottom of a secondary ink cartridge and vertically extends upwards to the top of the secondary ink cartridge; the liquid detection unit is mounted at a position at a preset height in the ink pipe and used for detecting whether the liquid level in the ink pipe reaches the preset height; and the alarm unit is electrically connected with the liquid detection unit and is used for alarming when the liquid detection unit detects that the liquid level in the ink pipe reaches the preset height. In the scheme, the alarm when the liquid level of the secondary ink cartridge is too high is realized, so that damage caused by ink overflow is capable of being prevented, and the development of a digital printing technology is facilitated.