Silicate modified polyurethane two-component spray gun and spraying method and cleaning method thereof

The invention discloses a silicate modified polyurethane two-component spray gun and a spraying method and a cleaning method thereof. The silicate modified polyurethane two-component spray gun comprises a spray gun switching mechanism, a feeding and discharging cleaning mechanism and a stirring and mixing mechanism. The spray gun switching mechanism comprises a fixed handle, a movable handle and a piston pull rod; the piston pull rod comprises a spring and a piston; the feeding and discharging cleaning mechanism comprises a feeding block and a discharging block; a material runner is arranged in the feeding block, a material runner and an air runner are arranged in the discharging block, and the feeding block is connected with the discharging block; the pull rod penetrates into a material runner of the feeding block from the outside of the feeding block, the piston is located in the material runner of the feeding block, and the spring is arranged between the piston and the end wall of the material runner in th