A driving method of an organic light-emitting display device, the organic light-emitting display device comprising a plurality of sub-pixels, each of the sub-pixels comprising a driving transistor, an organic light-emitting diode (OLED), and a sense line (S(n)) connected to the driving transistor and the organic light-emitting diode (OLED), the method comprising performing by the organic light-emitting display device the steps of: detecting threshold voltages of driving transistors of the sub-pixels by sense lines (S(n)); and calculating a first driving voltage according to all detected threshold voltages; transmitting the first driving voltage to a voltage generating circuit of a data driving circuit by a TTL signal, an I2C signal or a differential signal; generating data driving voltages based on the first driving voltage and image data, and applying the data driving voltages (V Data) to the sub-pixels, wherein, calculating the first driving voltage according to all the detected threshold voltages comprises: obtaining a maximum threshold voltage (Vth max) of all the driving transistors on the display device based on the detected threshold voltages of all the driving transistors, obtaining a corresponding image data voltage (V Datamax) which is the voltage to be supplied to the sub-pixels by the data driving circuit which makes all the organic light-emitting diodes (OLED) on the display device produce a maximum brightness; obtaining a first difference (ΔV1); and calculating a sum of the corresponding image data voltage (V Datamax), the first difference (ΔV1) and the maximum threshold voltage (Vth max), and taking a calculated result as a latest first analog driving voltage, comparing the latest first analog driving voltage value (V AVDD') with a stored first analog driving voltage value (V AVDD), and in a case that the latest first analog driving voltage value (V AVDD') is different from the stored first analog driving voltage value (V AVDD), storing the latest first analog driving voltage value (V AVDD')and taking the latest first analog driving voltage as the first driving voltage, and in the case that the latest first analog driving voltage value (VAVDD') is the same as the stored first analog driving voltage value (VAVDD), continuing to detect the threshold voltages of the driving transistors on the display device. detecting threshold voltages of driving transistors of the sub-pixels by sense lines (S(n)); and calculating a first driving voltage according to all detected threshold voltages; transmitting the first driving voltage to a voltage generating circuit of a data driving circuit by a TTL signal, an I2C signal or a differential signal; generating data driving voltages based on the first driving voltage and image data, and applying the data driving voltages (V Data) to the sub-pixels, wherein, calculating the first driving voltage according to all the detected threshold voltages comprises: obtaining a maximum threshold voltage (Vth max) of all the driving transistors on the display device based on the detected threshold voltages of all the driving transistors, obtaining a corresponding image data voltage (V Datamax) which is the voltage to be supplied to the sub-pixels by the data driving circuit which makes all the organic light-emitting diodes (OLED) on the display device produce a maximum brightness; obtaining a first difference (ΔV1); and calculating a sum of the corresponding image data voltage (V Datamax), the first difference (ΔV1) and the maximum threshold voltage (Vth max), and taking a calculated result as a latest first analog driving voltage, comparing the latest first analog driving voltage value (V AVDD') with a stored first analog driving voltage value (V AVDD), and in a case that the latest first analog driving voltage value (V AVDD') is different from the stored first analog driving voltage value (V AVDD), storing the latest first analog driving voltage value (V AVDD')and taking the latest first analog driving voltage as the first driving voltage, and in the case that the latest first analog driving voltage value (VAVDD') is the same as the stored first analog driving voltage value (VAVDD), continuing to detect the threshold voltages of the driving transistors on the display device. obtaining a maximum threshold voltage (Vth max) of all the driving transistors on the display device based on the detected threshold voltages of all the driving transistors, obtaining a corresponding image data voltage (V Datamax) which is the voltage to be supplied to the sub-pixels by the data driving circuit which makes all the organic light-emitting diodes (OLED) on the display device produce a maximum brightness; obtaining a first difference (ΔV1); and calculating a sum of the corresponding image data voltage (V Datamax), the first difference (ΔV1) and the maximum threshold voltage (Vth max), and taking a calculated result as a latest first analog driving voltage, comparing the latest first analog driving voltage value (V AVDD') with a stored first analog driving voltage value (V AVDD), and in a case that the latest first analog driving voltage value (V AVDD') is different from the stored first analog driving voltage value (V AVDD), storing the latest first analog driving voltage value (V AVDD')and taking the latest first analog driving voltage as the first driving voltage, and in the case that the latest first analog driving voltage value (VAVDD') is the same as the stored first analog driving voltage value (VAVDD), continuing to detect the threshold voltages of the driving transistors on the display device.