The invention belongs to the technical field of hoisting machineries and discloses an intelligent rollover preventing system for a crane. The end part of each vertical movable supporting leg is connected with a leg support plate; each left support plate is provided with a sensing switch matched with the corresponding vertical movable supporting leg; a two-position three-way electromagnetic reversing valve is used for controlling the connection and disconnection of an oil channel between a lower operation multi-way valve and an upper operation multi-way valve; a power supply, a pressure relay,the four sensing switches and an integrated circuit module are sequentially connected in series to form a loop; the four sensing switches are used for controlling the connection and disconnection of the pressure relay; a self-locking circuit and the pressure relay are connected in parallel; the integrated circuit module is used for controlling the connection and disconnection of the self-locking circuit; the power supply, a normally-open switch and the two-position three-way electromagnetic reversing valve are sequentially connected in series to form a loop; and the integrated circuit module is used for controlling the connection and disconnection of the normally-open switch. The invention also discloses the crane which comprises the intelligent rollover preventing system for the crane. The intelligent rollover preventing system provided by the invention can be used for monitoring the work conditions of the lorry-mounted crane in real time and effectively prevents the phenomenon of rollover caused by leg warping of a lorry and slight sinking of the ground.