The invention discloses a cesium releasing agent for realizing low-temperature controlled release of cesium and a manufacturing method of a releaser used for the cesium releasing agent, belonging to the field of cesium releasing agents for third-generation low-light level night vision devices and releasers used for the cesium releasing agents. The cesium releasing agent comprises a cesium salt and a reducing agent, wherein the cesium salt is cesium chromate or cesium tungstate, and the reducing agent is a modified ZrVFe getter. The releaser is produced by processing an NiCr alloy pipe, a Cs steam escape outlet is formed through laser boring in the pipe, the middle part of the pipe is filled with the cesium releasing agent and is subjected to press molding, and meanwhile two ends of the pipe are clamped to be flat so as to be used as heating electrodes. If being put into a low-light level night vision device, the manufacturedreleaser is found to have the cesium releasing temperature of 300-500 DEG C and the cesium releasing frequency of 300-400 times and to be freeof releasing harmful impurity gases and controllable in release rate and release amount; and the steam escape outlet of the releaser is reasonably designed, and the evaporation uniformity of Cs on a photoelectric cathode is good, so that the performance of the photoelectric cathode with negative electron affinity (NEA) is remarkably improved.