An OLED display device is provided. The OLED display device includes a first transistor connected to a data line and a first node; a second transistor connected to the first node and a second node; a third transistor connected to a reference voltage terminal and a third node; a fourth transistor connected to an initialization voltage terminal and the second node; a fifth transistor connected to the reference voltage terminal and the second node; a driving transistor; and an OLED connected to a low-level power supply voltage terminal and the second node. The driving transistor has a source connected to the second node, a gate connected to the third node, and a drain connected to a high-level power supply voltage terminal.