A nonlinear optimal interval scheduling model for combined cooling, heating and power (CCHP) microgrid with multi approaches of energy conversion is proposed. First,to improve the consumptive capacity of wind power, photovoltaic and other renewable energy, a flexible CCHP microgrid system with the ability of energy conversion of electric energy to cooling, electric energy to thermal energy and energy to cooling energy is built.Then in the CCHP microgrid,Considering the fluctuation of wind power, photovoltaic, cooling load, thermal load and electricity load, an optimal scheduling model is proposed.It is a nonlinear interval optimization model with the lowest system cost as the goal,the factors of environmental benefit,TOU power price and operation and maintenance cost taken into account. According to the method of interval possibility , the uncertainty model is transformed into a deterministic model and the improved particle swarm optimization algorithm is applied to solve the deterministic model.Finally,taking a CCHP microgrid system for a simulation example,the rationality and flexibility of the proposed model is verified and influence of load fluctuation and interval probability on system operating cost is analyzed.