The invention relates to the technical field of communication equipment and discloses a mobile vehicle-mounted WiFi device. The device comprises a machine frame, a sliding rail is fixedly connected tothe machine frame, a sliding block is in sliding connection with the sliding rail, a WiFi emitter is installed in the sliding block, a rack is in sliding connection with the sliding block , an auxiliary antenna is installed on the rack, a first air chamber is fixedly connected to the sliding block, a first turbine is rotationally connected to the inside of the first air chamber, and a gear is coaxially connected to the first turbine; piston cylinders are fixedly connected to the machine frame, and pistons are in sliding connection with the inner portions of the piston cylinders and fixedly connected with piston rods; an elastic ball is fixedly connected to the sliding block, a first inner cavity and a second inner cavity are formed in the elastic ball, a hitting block is arranged in the first inner cavity, a second spring is connected between the hitting block and the elastic ball, and an air bag is circumferentially and annularly connected to the sliding block. The device further comprises a controller and switches, the switches are evenly distributed in a vehicle, and the controller is electrically connected with a drive mechanism and the switches. By the adoption of the device,vibration of the device can be reduced, comprehensive WiFi coverage is achieved, and a network use effect is improved.