The invention provides a low-nitrogen condensation type double-hearth gas boiler system, and belongs to the technical field of environmental protection equipment. The system solves the problems that an existing gas boiler is poor in energy-saving effect during use and the like. The system comprises hearths, a convection chamber, anti-explosion door devices, a waste heat recovery energy-saving device and a low-nitrogen combustion device, an upper boiler barrel and a lower boiler barrel are arranged on the upper part and the lower part of the convection chamber correspondingly, a convection tubebundle is arranged between the upper boiler barrel and the lower boiler barrel in a connecting mode, each hearth comprises a main hearth and an auxiliary hearth which are separated from each other, the main hearth and the auxiliary hearth of each hearth are provided with a main combustor and an auxiliary combustor correspondingly, the main hearths and the auxiliary hearths communicate with the convection chamber, the anti-explosion door device is arranged on the outer wall of each main hearth, the waste heat recovery energy-saving device is in butt joint with the convection chamber to be usedfor recycling waste heat of the flue gas to be discharged, and the low-nitrogen combustion device can enable the fuel to be sufficiently combusted. According to the system, the problem of boiler energy efficiency caused by large load fluctuation of users can be well solved.