A vehicle burglar-proof device comprises a base installed below a cushion of the seat; two tracks being arranged at two sides; the base being arranged across inner sides of two tracks; a mask enclosing a top and lateral sides of the base; a motor arranged within the base for driving the base to move along the two tracks; a control unit for conducting the motor. When a front side of the mask moves forwards to resist against a body of a vehicle, the controlling pedals will be isolated and the motor is interrupted so as to buckle and confine the base; and thus, the control pedals cannot be pressed so that they cannot be enabled.