Provided are an OLED pixel circuit and a driving method thereof, and a display device. The OLED pixel circuit includes: an initialization sub-circuit coupled to a driving sub-circuit, a first signal terminal, a first voltage terminal and an initial voltage terminal, respectively, and configured to initialize the driving sub-circuit; a data writing and compensation sub-circuit coupled to the driving sub-circuit, a scan signal terminal and a data voltage terminal, respectively, and configured to perform threshold voltage compensation for the driving sub-circuit; the driving sub-circuit further coupled to a light-emitting control sub-circuit and the first voltage terminal, and configured to drive a light-emitting sub-circuit to emit light after threshold voltage compensation has been performed.