Safety joint for well drilling

The utility model relates to a safety joint for well drilling. According to the technical scheme, a male connector is connected to the upper end of a female connector in an inserted mode, a supportingcylinder is installed in the male connector, the male connector and the supporting cylinder are fixedly connected through a shear pin, two sets of through grooves are formed in the lower portion of the male connector, locking mechanisms are arranged in the through grooves, and clamping grooves matched with the locking mechanisms are formed in the corresponding positions of the inner wall of the upper portion of the female connector. The connector has the beneficial effects that the locking mechanism pushes the locking block to be embedded into the clamping groove through the supporting cylinder, so that the male connector and the female connector are fixedly connected together; when working conditions such as drill jamming occur; shearing shear pin, the support cylinder falls into the support cylinder falling cav