Cement mortar repairing system and method for building construction

The invention discloses a cement mortar repairing system and method for building construction, and belongs to the field of building construction. A cement mortar repairing system for building construction comprises a cart and further comprises a stirring tank with a discharging pipe arranged at the lower end, the stirring tank is fixedly installed at the upper end of the cart, a cover plate is detachably installed on an upper end opening of the stirring tank, and a stirring mechanism is arranged in the stirring tank; the conical discharging nozzle is fixedly connected to the tail end of the discharging pipe through a hose, a valve is fixedly installed on the discharging nozzle, an automatic pressurizing assembly is arranged at the upper end of the cover plate, and the automatic pressurizing assembly is connected with a stirring mechanism; the cement mortar can be prevented from being solidified, filling and trowelling work of the cement mortar can be automatically completed, and the cement mortar filling and