The following principles should be adopted in the design of solar energy wastewater treatment process on the basis of fully understanding the actual operation water quality and quantity in rural areas and making full reference to the similar treatment process in rural areas. Guided by the overall planning and construction of rural villages and towns, combined with the characteristics of solar sewage treatment equipment, taking into full account the combination of internal and external, the sewage treatment project becomes a complete and unified project. 2. The selection of reliable, advanced technology, low investment, low operating costs, simple management, flexible operation of solar sewage treatment equipment and equipment, for the operation of the sewage treatment system to create good conditions. 3. According to the requirements of the environmental protection policy, the design of the effluent to meet the first-class b emission standards.