The invention discloses a cleaning method and device for a floor heating system. The method comprises that first pressure values of water inlet pipes and second pressure values of water outlet pipes of rooms laid with the floor heating system are collected; and the floor heating system of the room is cleaned according to the pressure difference of the first pressure values and the second pressure values. The cleaning method and device solve the problems that a filter of the floor heating system is blocked and the floor heating fails due to the fact that the floor heating system cannot be cleaned for a long time, the pipeline cleaning of the floor heating system is achieved, and manpower and material resources are saved.