The kinematics and dynamics modeling and control of the four-DOF underwater manipulator were studied. The structure of the underwater manipulator was designed systematically, and the inverse kinematics and dynamics were analyzed by means of homogeneous variation method and Newton-Euler method respectively. The relevant motion simulation was carried out by using MATLAB, and the rationality of the structure design was verified. The manipulator control system was studied, and then through the analysis and design of the control scheme and the signal transmission and conversion, the motion control for the manipulator was realized.