The disclosure provides an all-solution OLED device and a manufacturing method thereof. The manufacturing method fabricate a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode by solution film-forming. Compared with the manufacturing method of the existing OLED device, an all-solution fabrication of the electron transport layer and the cathode is achieved, the use of high vacuum evaporation process and equipment can be avoided, thereby saving materials and reducing manufacturing costs; and the adjacent layers will not appear mutual solubility, so the film quality is high and the device performance can be improved. The hole injection layer, the hole transport layer, the light emitting layer, the electron transport layer, and the cathode are all fabricated by solution film-forming; and compared with the existing OLED device, the manufacturing cost is low, the film-forming quality is high, and the display quality is excellent.