A grouting device for automatic joint filling machine is developed to improve the automation level and quality of curb joint filling. The structural characteristics of the curb joints are analyzed through field investigation, and the width and height errors of the joints are determined. Based on this, a grouting device combining the crank slider mechanism and parallel quadrilateral mechanism is designed to realize the clamping of the curb and the uniform filling of cement. In the grouting process control, the innovative method of combining time and pressure is adopted to estimate the filling time according to the flow rate of the screw conveyor, and the pressure gauge at the grouting mouth is used to monitor the pressure change to ensure the accuracy of grouting. Through theoretical analysis, a mathematical model is established, and the force of the mechanism is analyzed deeply on the basis of considering the deformation force of flexible materials. The geometric dimensions of the mechanism are studied in working and non-working states. Using MATLAB simulation analysis to determine reasonable geometric parameters to balance the force. Complete the structural design and functional verification, and meet the engineering requirements of automatic construction of curb joint filling.