Abstract: Xinjiang is the largest agricultural production base in China; however, due to the region's unique climate, early sowing is not possible. The use of seedling transplanting technology has been adapted to extreme climatic conditions, and this technology has improved the survival rate of tomato seedlings. As tomato production continues to expand and agricultural modernisation advances, the efficiency of transplanting machinery is becoming an essential development requirement. The present study proposes a non-singular fast terminal sliding mode control method based on the interference observer, with the aim of enhancing the system's seedling picking up and delivery mechanism. This method addresses the challenges posed by interference and modelling errors, which have been identified as contributing factors to the system's suboptimal performance, characterised by low position control accuracy, slow response speed and stability. 1)The paper analyses the constraints on the seedling pickup and delivery mechanism, and establishes a reduced order model of seedling pickup and delivery manipulator dynamics based on the Lagrange dynamics modelling method. 2)The non-singular fast terminal sliding mode controller is designed, and the improved fal function convergence law is adopted to ensure the fast and accurate position control of the seedling pickup and delivery mechanism. 3)Due to the jitter vibration caused by the nonlinear function and friction vibration in the controller, it is proposed to introduce a nonlinear disturbance observer to achieve effective suppression of the jitter vibration and stability of the system tracking. 4)In Matlab/Simulink, the trajectory tracking simulation experiment of transplanting machine seedling pickup and delivery mechanism under interference is carried out. The results demonstrate that the position tracking of the seedling pickup and delivery mechanism linkage 1 and linkage 2 converge at 0.7 and 0.8s, respectively, when employing a non-singular fast terminal sliding mode controller. The maximum position tracking error is 0.32 and 0.45rad, which verifies that the sliding mode controller effectively improves the convergence speed and control accuracy of the seedling pickup and delivery mechanism. After the introduction of the interference observer, the mean squared error of position tracking of connecting rod 1 and connecting rod 2 of the seedling pickup and delivery robot is 0.00772 and 0.00824rad, which is a decrease of 45.7% and 52.8% in the tracking error mean squared error, and it verifies that the interference observer effectively improves the stability of the control. Concurrently, the convergence time is reduced by 42.9% and 25%, and the maximum position tracking error is decreased by 25% and 11%, signifying that the interference observer enhances convergence speed and control accuracy. Finally, a test platform has been constructed in order to verify the rate of seedling pickup and delivery and error accumulation through the use of high-speed photography. The results of this study demonstrate that the maximum attitude error in the rate test of seedling pickup and delivery is 2.63°, and that the error accumulation test is within 3°, which meets the actual working requirements of seedling pickup and delivery. This study provides a reference for the automation of pickup and delivery of tomato hole tray seedling transplanter.