Provided are an external compensation circuit and method, and display device in the field of display techniques. The external compensation circuit includes a regulation sub-circuit that may collect a driving current loaded to a light-emitting unit and a reference current from a reference current source, and regulate potentials at two nodes connected to a compensation sub-circuit according to the collected current, to enable the compensation sub-circuit to calibrate a data signal to be input to a pixel circuit according to a potential difference between the two nodes.