The invention discloses a preparation method of solid waste surface in-situ growth nano-particles. The method includes the steps: (1) preparing carbonized salt solution, adding untreated or treated solid waste into the carbonized salt solution, adding surface active agents and emulsifying agents or crystal conditioning agents, and uniformly pre-stirring mixture; (2) placing the solution acquired in the step (1) into a carbonization reaction device, leading in CO2 gas, stirring and reacting mixture, and stopping reaction when a pH (potential of hydrogen) value of the solution is reduced by 7-8;(3) washing products after reaction, separating solid-liquid phases, drying a solid phase to obtain the solid, namely the nano-particles. By the aid of a one-step preparation process of a micro-bubble carbonization method, preparation of nano-materials and a mineral sealing technology of SO2 are achieved through the same process, in-situ growth of different nano-particles on the solid waste surface can be achieved, the preparation method is widely applied to production of building materials and utilization and treatment of the solid waste, a preparation process is simple and convenient, green, environmentally friendly and low in cost, and by-products can be recycled.