The invention provides a multifunctional gantry crane anti-collision device and belongs to the technical field of hoisting machinery. The problem that accidents are caused by collision of gantry cranes in the prior art is solved through the multifunctional gantry crane anti-collision device. The multifunctional gantry crane anti-collision device comprises gantry cranes. A single-piston type double-rod hydraulic oil cylinder is arranged on a supporting leg of one of the gantry cranes. A touch receiver is arranged on the other gantry crane on a track. The hydraulic oil cylinder is provided with a communicating pipeline communicating with cavities in the two ends of a piston. An on-off control valve is arranged on the communicating pipeline. A cylinder body of the single-piston type double-rod hydraulic oil cylinder is fixed to the supporting leg. After the touch receiver receives collision of a piston rod of the single-piston type double-rod hydraulic oil cylinder, a brake of the gantry cranes is in a reverse rotation braking state. According to the multifunctional gantry crane anti-collision device, the moving gantry crane can be stopped, and the original stopped gantry crane can move subsequently after being collided, so that greater damage is avoided.