The invention relates to a fly ash washing cement kiln collaborative disposal and resource comprehensive utilization system and method. The system includes: a fly ash rinsing and solid-liquid separation unit, a fly ash wet mud backmixing, drying and kiln entry unit, a fly ash washing liquid pretreatment unit and an MVR evaporative crystallization and potassium-sodium separation unit. The fly ash rinsing and solid-liquid separation unit is respectively connected to the fly ash wet mud backmixing, drying and kiln entry unit and the fly ash washing liquid pretreatment unit, and the fly ash washing liquid pretreatment unit is respectively connected to the MVR evaporative crystallization and potassium-sodium separation unit and the fly ash wet mud backmixing, drying and kiln entry unit. The system provided by the invention is a resource recycling and comprehensive utilization system, and completely has no discharge of wastewater and waste residue. The fly ash washing cement kiln collaborative disposal and resource comprehensive utilization method provided by the invention is simple, the system setting is reasonable, and by combining the technological characteristics of cement kiln, harmless, reduction and recycling disposal of waste incineration fly ash in large scale can be realized.