Abstract: Aiming at the problem of automatic alignment in the field of agricultural transplanting machine, combined with digital image processing technology and inertial navigation technology, according to the operation characteristics of transplanting machine,this paper developed an agricultural machinery integrated navigation system with high precision, strong robustness and low cost.Firstly, the boundary of transplanted Ophiopogon japonicus was judged by visual algorithm and the navigation line was extracted, so as to obtain the relative position and attitude information of the carrier based on visual algorithm, then the Kalman filter algorithm was used to optimally estimate the output data of the inertial navigation system, so as to obtain the optimal navigation parameters of the carrier. Taking Ophiopogon japonicus transplanter as the carrier, experimental results showed that the integrated navigation scheme with high precision, strong robustness and low cost, could effectively solve the problem of automatic alignment in the operation process of Ophiopogon japonicus transplanting machine, and realize the automatic transplanting of Ophiopogon japonicus.