In-situ repairing method and system for ultra-high performance concrete in narrow space

The invention provides an ultra-high performance concrete in-situ repairing method and system in a narrow space. A double-shaft stirring barrel comprises a barrel cover, a stirring barrel body, a double-shaft stirring shaft and a discharging barrel, the double-shaft stirring shaft is arranged in the stirring barrel body, a rotary opening and closing discharging opening is formed in the bottom of the stirring barrel body, and the discharging barrel is arranged below the stirring barrel body; the machine box is arranged below the double-shaft stirring barrel, a first motor, a second motor, a pump machine and a controller are arranged in the machine box, the controller is provided with a control panel in a matched mode, the pump machine is provided with a pump pipe in a matched mode, and the second motor is electrically connected with the double-shaft stirring shaft; the inner surface of the intelligent formwork is smooth, a pouring cavity is defined on the scabbled surface of the to-be-repaired structure, and a