3D printing bone tissue engineering drug-loaded stents are developed toward multi-materials.Aiming at the nozzle collision interference,common spot printing and salivation caused by the switching of multiple nozzles during the printing of multi-material stents,a multi-nozzle 3D printing system based on motor extrusion deposition and a multi-nozzle controlling method were proposed.The switching structure of petal-shaped printing nozzle for multi-material was presented.The path planning of multi-nozzle switching and PC control software were designed.Finally,a mixed material of hydroxyapatite and polyvinyl alcohol was tested on the multi-nozzle biological 3D printing system.The research results show that the system can be used to realize the coordinated printing and co-point printing of multiple nozzles,the interference collision and salivation phenomenon generated by nozzle switching during printing are solved.It provides reference for gradient printing of biomimetic drug-loaded tissue engineering bone scaffolds.