Embodiments of the invention provide a positioning method and device based on a positioning model, which are applied to a positioning system comprising a plurality of nodes. The method comprises the following steps of receiving signal strength of a point to be positioned by any node in the positioning system; taking the signal strength of the point to be positioned as an input of the positioning model, and determining a positioning position of the point to be positioned by utilizing the positioning model, wherein the positioning model is established based on all the nodes in the positioning system and comprises a plurality of layers, the first layer is used for each node to receive the signal strength broadcast by other nodes respectively and carry out weighting on the received signal strength of the other nodes in order to obtain a first weighted signal strength value of each node, and the Mth layer is used for any node to receive an M-1th weighted signal strength value of each node and carry out weighting on the M-1th weighted signal strength value of each node to obtain an Mth weighted signal strength value of any node; and determining the position of each node based on the Mthweighted signal strength value of any node according to a preset mapping relation between the signal strength and the position.