The invention discloses an energy-saving 
heat supply system with a function of reducing the temperature of 
heat supply return water, and belongs to the field of improvement of energy utilization efficiency. Heat exchange can be repeatedly carried out on heat sources by multistage heat exchangers, multistage absorption heat exchange units, multistage compression heat pumps and an ice making type refrigerator, accordingly, the 
heat supply areas can be enlarged, and the energy utilization efficiency can be improved. The energy-saving heat supply 
system has the advantages that the temperature of the return water of heat supply primary 
pipe networks can be reduced and reach 0 DEG C, the return water contains 10% of ice particles, accordingly, 
route heat loss of the return water of the heat supply primary 
pipe networks can be reduced, the 
temperature difference of the return water of the heat supply primary 
pipe networks can be increased and reaches 118 DEG C from the original 60 DEG C, the flow rate of circulating water of the heat supply primary pipe networks can be lowered, 
energy consumption of circulating pumps can be reduced, heat supply flow rates of a user side can be greatly increased, the 
delivery efficiency of the pipe networks can be improved, the heat supply scale can be expanded, 
waste heat of a 
cooling tower can be recycled, and the like.