The present disclosure provides a backlight module and a method of manufacturing the backlight module. Through splicing a light panel on a reinforcing plate and fixing with a double-sided tape, and then performing a membrane pressure press or a casting process to the backlight module, forms a fluorescent film of mini-LED as a whole surface structure, in a bid to prevent waveguide blocking light in propagation of the fluorescent film, thereby improving a problem of splicing dark line.