This disclosure provides an OLED substrate and a producing method thereof, a panel, and a display apparatus, and pertains to the field of OLED products and production. The OLED substrate comprises an OLED device and an encapsulating layer, which are located on a first substrate, wherein the encapsulating layer encapsulates the OLED device, and wherein the OLED substrate further comprises a heat-dissipating layer which is provided above the OLED device. By adding a heat-dissipating layer and by means of the good thermal conductivity of the heat-dissipating layer, the heat generated when OLED devices are lit is rapidly dissipated, so as to prolong the service life of OLED devices, such that the service life of OLED panel and in turn the service life of display apparatus are prolonged.