The invention mainly relates to a spray repair method for the lining of a kiln firebrick in smelting and chemical industries and the like, comprising technical processes such as scene pretreatment, spray repair, maintaining and scene heat treatment. Aiming at the damaged firebrick linings of inner walls of a roasting kiln, a sulfur kiln and a waste heat boiler in smelting and chemical industries and the like, powder-shaped high temperature fireproof material is sent to a spray pipe by directly utilizing an air compressor and an injector and then sprayed on the firebrick or a steel board needing repairing by high pressure after mixed with a certain proportion of water in a transfer piping. The method is a recovery repair technology, and is characterized in that thorough repair treatment can be carried out on line as long as the spraying pipe can be stretched to the position needing repairing in the premise of no need for removing or bricking again; and the method has simple and effective procedure, short construction time and low repair cost, thereby effectively repairing the firebrick lining dropping from the inner part of the kiln, prolonging the service life of the kiln and guaranteeing long-term normal operation of equipment.