A coating device includes an autoclave and a spray member. The autoclave includes an autoclave body and a cover sealing the autoclave body. The autoclave body defines a plurality of holding grooves in an inner surface thereof for holding substrates. The spray member is positioned on the cover and received in the autoclave body. The spray member defines openings in a side surface thereof. The spray member includes a container and an ultrasonic atomization unit. The container defines a cavity in communication with the openings. The ultrasonic atomization unit is received in the cavity.