This paper first conducts a kinematic analysis of the bulldozer’s working device, deriving the transformation matrices between each joint and formulating the relationship between the blade’s end-effector position and orientation and the joint angles in the Cartesian coordinate system. Next, using a geometric method, the joint space of the working device is converted into the drive space, clarifying the mapping relationship between joint angles and the hydraulic cylinder’s extension length. Finally, a simulation model of the working device’s linkage mechanism is established, and four sets of joint angles are selected to verify the forward and inverse kinematics analysis. Additionally, a simulation model of the working device’s hydraulic system is developed, experimental parameters are set, and the accuracy of the relationship between the joint angles and the hydraulic cylinder’s extension length is validated. This provides a theoretical foundation for subsequent research on the operation planning and control of unmanned bulldozer working devices.