The invention discloses a novel energy-saving and environment-friendly fuel and a fuel combustor. The novel energy-saving and environment-friendly fuel is directly prepared by compounding heavy oil, a biomass fuel and a fuel additive by the fuel combustor along a production line during combustion, wherein the substances are mixed and combusted at the same time; the weight ratio of the heavy oil to the biomass fuel to the fuel additive of the novel energy-saving and environment-friendly fuel is (5-7) to (3-2) to (2-1). The fuel additive comprises water, an emulsifying agent, a desulfurizing agent, a calorific value increasing agent and a lubricating agent in the weight ratio of 44 to 10 to 5 to 40 to 1 and the components are independently prepared. The novel energy-saving and environment-friendly fuel combustor breaks through the energy conservation and environmental protection bottleneck that the conventional combustor can only combust single oil such as the heavy oil. By using the fuel combustor and the novel energy-saving and environment-friendly fuel, enterprises and public institutions of first-tier large and medium-sized cities can mainly select the heavy oil which has relatively low cost and high calorific value and serves as a basic fuel, so the fuel cost is reduced and the problem of pollution of combustion exhaust is synchronously and completely solved.