A waterproof casing for packaging a circuit board having an antenna includes a housing, a waterproof gasket, and an end cover. The housing has an accommodation space and a side opening communicating with each other. The accommodation space is configured to accommodate the circuit board. The waterproof gasket includes a main body and an extending portion. The main body covers the side opening. The extending portion extends from the main body. The end cover abuts against a side of the main body away from the accommodation space, and is fixed to the housing to form a box with the housing. The box has a communication opening positioned corresponding to the antenna. The extending portion hermetically covers the communication opening.