Plastic spraying process for bearing retainer, the process comprising the following process steps: step 1: pretreatment to the bearing retainer: carrying out rust removal and decontamination treatment on the bearing retainer; step 2: plastic spraying treatment on the bearing retainer: putting the bearing retainer treated in the step 1 into a plastic spraying device to carry out plastic spraying treatment on the bearing retainer, a thickness of the coating obtained by the spraying treatment is no less than 10 microns; step 3: heat-curing treatment on the bearing retainer: putting the bearing retainer treated in the step 2 into a heating furnace for heating and curing, heating temperature is not lower than 80 °C, and heating time is no less than 5 minutes; step 4: cooling treatment on the bearing retainer: cooling the bearing retainer down after taking the bearing retainer treated in the step 3 out of the heating furnace, and cooling temperature is not higher than 80 °C; characterized in that in step 3, the bearing retainer is moved vertically in the heating furnace; and the heating furnace used in step 3 includes a furnace body, a device of vertical circulation is fixedly disposed in the furnace body, and a fixing member is provided on the device of vertical circulation, a tray is horizontally placed in the furnace body, and the tray is provided with a detachable member, the detachable member provided on the tray is so adapted as to be able to be mounted on the fixing member provided on the device of vertical circulation, a feed port is provided on a left side of the furnace body, and a discharge port is provided on a right side of the furnace body, and the feed port and the discharge port are not arranged on a same horizontal line; step 1: pretreatment to the bearing retainer: carrying out rust removal and decontamination treatment on the bearing retainer; step 2: plastic spraying treatment on the bearing retainer: putting the bearing retainer treated in the step 1 into a plastic spraying device to carry out plastic spraying treatment on the bearing retainer, a thickness of the coating obtained by the spraying treatment is no less than 10 microns; step 3: heat-curing treatment on the bearing retainer: putting the bearing retainer treated in the step 2 into a heating furnace for heating and curing, heating temperature is not lower than 80 °C, and heating time is no less than 5 minutes; step 4: cooling treatment on the bearing retainer: cooling the bearing retainer down after taking the bearing retainer treated in the step 3 out of the heating furnace, and cooling temperature is not higher than 80 °C; characterized in that in step 3, the bearing retainer is moved vertically in the heating furnace; and the heating furnace used in step 3 includes a furnace body, a device of vertical circulation is fixedly disposed in the furnace body, and a fixing member is provided on the device of vertical circulation, a tray is horizontally placed in the furnace body, and the tray is provided with a detachable member, the detachable member provided on the tray is so adapted as to be able to be mounted on the fixing member provided on the device of vertical circulation, a feed port is provided on a left side of the furnace body, and a discharge port is provided on a right side of the furnace body, and the feed port and the discharge port are not arranged on a same horizontal line;