The invention discloses a printed circuit board layout method and system. The printed circuit board layout method is characterized in that a processing unit and a storage unit are involved in printed circuit board layout. The storage unit stores entity node data and virtual node data. The processing unit is electrically coupled with the storage unit and used for executing the following steps that the entity node data and the virtual node data are obtained, wherein the entity node data includes multiple entity node data structures, on a printed circuit board, of multiple entity nodes and multiple entity node coordinates, and the virtual node data includes multiple virtual node data structures, on the printed circuit board, of multiple virtual nodes; the corresponding relation between the entity nodes and the virtual nodes is judged according to the entity node data and the virtual node data; the virtual nodes are placed into the entity node coordinates.