The invention provides a boiler sewage waste heat recovery system. A boiler, a sewage storage tank, a sewage heat pump, a sewage vaporization tank, a high-pressure Roots blower, a heat exchanger and asteam separator are sequentially arranged in a high-temperature sewage and atomizing gas flow direction. The top of the vaporization tank is provided with a gas outlet, the inner upper portion of thevaporization tank is in rotational connection with a centrifugal atomizing sieve barrel in vertical arrangement, and a centrifugal turbine positioned above the centrifugal atomizing sieve barrel is fixed to the same. The vaporization tank is provided with one or more sewage ejectors on the periphery of the centrifugal atomizing sieve barrel, each sewage ejector is provided with a sewage inlet anda jet orifice, sewage pumped from the sewage heat pump flows into each sewage inlet, jetted to the centrifugal atomizing sieve barrel from each jet orifice and atomized finally, the centrifugal atomizing sieve barrel and the centrifugal turbine are pushed to rotate, and atomized gas flows from the gas outlet to the high-pressure Roots blower and the heat exchanger to heat softened water. The boiler sewage waste heat recovery system has advantages that sewage heat energy is recycled completely, and long-term operation of equipment is realized.