Slope protection lining mortar pointing device and using method

The invention discloses a slope protection lining mortar pointing device and a using method. The pointing device comprises a pointing groove spray pipe, a mortar injection pipe, a positioning support, a mortar guide-in pipe, a connector, a flow control valve and a mortar pump pipe. The positioning support of the frame structure is arranged on the mortar injection pipe in a sleeving mode. The upper end of the mortar injection pipe is connected with the mortar ingress pipe; the mortar ingress pipe is connected with the mortar pump pipe through the connector, and the flow control valve is arranged between the connector and the mortar ingress pipe. During use, the positioning support is supported on a lining for positioning, a worker holds and presses the operation handle downwards with two hands, the pointing groove spray pipe is pressed downwards until the pointing groove spray pipe is tightly attached to two edges of a mortar pointing groove, the flow control valve is opened, and mortar is injected into the mo