Provided is a substrate positioning device, comprising a datum plane which can transmit substrates one by one and moves horizontally. Firstly, an end positioner stops the movable substrate of the datum plane, and then a side edge positioned contacts with and corrects the substrate of the datum plane, and finally a lifter lifts the substrate to leave the datum plane through movement from bottom up. The device stops and positions the substrate through mechanical assemblies, so as to remove configuration of sensing components.