In the magnetic resonance imaging environment, it is difficult for breast biopsy robot to obtain highquality scanned images and precise biopsy needle interventions due to material and drive compatibility. Therefore, a double tendonsheath flexible system with lebus grooves used on the robots, that could meet the requirements of nuclear magnetic compatibility, longdistance and largestroke transmission is proposed in this paper. Firstly, the friction analysis of the single joint is implemented for the double tendonsheath remote transmission system with lebus grooves. A bidirectional coupling transmission model is formulated based on the analysis of nonlinear coupling characteristics of the singlejoint double tendonsheath transmission. The experimental platform of singlejoint bidirectional coupling transmission is established, and the analysis and compensation experiments of singlejoint bidirectional coupling transmission are carried out. Secondly, a multijoint breast biopsy robot experimental platform with double tendonsheath transmission is built. In addition, the analysis of bidirectional coupled motion error and compensation experiment are performed on the multijoint breast biopsy robot with double tendonsheath transmission. After compensation, the average error in the X, Y, and Z directions of the needle tip entering the tissue are 139, 189, and 160 mm, respectively. Experimental results verify that the multijoint breast biopsy robot with double tendon sheath transmission can meet the precision requirements of breast biopsy under nuclear magnetic environment.