The invention discloses a central control device and method for multiple SCR systems. The device comprises the multiple SCR systems, an urea storage tank, an air compressor, a distributed type controlsystem and a main control system. The distributed type control system controls a filling pump to work according to a low-liquid-level signal of a first liquid level sensor and fills an urea tank withurea from the urea storage tank; the distributed type control system controls the air compressor to work according to a gas pressure signal of a gas pressure sensor to keep the gas pressure of a jetnozzle in a preset level; and the main control system is used for gathering and displaying information of the distributed type control system and each SCR system. The central control device and methodfor the multiple SCR systems are suitable for tail gas purifying of large diesel engine sets, cabinets of the multiple SCR systems can be put at different positions according to actual demands, the urea storage tank, the distributed type control system and the main control system can be arranged at the positions which are conveniently managed, and great convenience is achieved.