In view of the difficulty of clearing forest, cutting irrigation and subsequent transportation, processing and packaging in complex forest environments in some areas of China, a shrub harvesting device with high efficiency of cutting irrigation and clearing forest was designed. The three-dimensional modeling of the manipulator is carried out, the dynamic analysis of the manipulator is analyzed by using ADAMS software, and the static analysis and modal analysis are analyzed by using Ansys finite element software, so as to obtain the mechanical condition and resonance of the manipulator. According to the data obtained, the parameters of the manipulator are optimized and improved. The static analysis of the manipulator shows that the maximum stress of the manipulator is 109.25 MPa, the maximum deformation is 8.055 6 mm, and the first-order minimum frequency of the manipulator is 69.194 Hz. The results show that the length of the manipulator is 901.5 mm, the thickness of the manipulator is 8.4 mm, the size of the hinge hole is 52.2 mm and the thickness of the hinge is 7.22 mm. In this paper, the structure of the manipulator is designed and simulated to verify the rationality of the strength and stiffness of the manipulator in operation. It is concluded that the improved manipulator design meets the stability requirements, which is of great significance to the whole moving process of the machine. The machine can be widely used in forestry collection, packaging and transportation industries.