The invention discloses an energy-saving and environment-friendly water-steam dual-purpose boiler. Fuel of the boiler enters the boiler from a feeding channel and freely falls onto fire grates on the upper layer to be combusted, fuel not completely combusted falls onto fire grates at the lower portion to be continuously combusted and is blown up through inlet air of an air inlet channel, then, the fuel passes through the part between main heating pipes and moves downwards, and then the fuel passes through the part between auxiliary heating pipes; at the moment, dust falls into a dust collecting bin and a dust removing channel, hot air and newly-incoming inlet air move upwards together, the hot air is supplemented to the fuel on the upper fire grates, high-temperature flames heat annular water boiling tanks, steam heating pipes and a steam tank, and due to the fact that inlet water of the annular water boiling tanks mainly comes from the main heating pipes, the water can boil only through slight heating, the boiled water enters the steam heating pipes, steam is formed, the steam enters the steam tank to be further heated, and the temperature can reach more than 170 DEG C. The boiler can produce the boiled water and the steam at the same time, meanwhile, the fuel is combusted thoroughly, and energy saving and environment friendliness are achieved.