This technology can optimize the design of the ply-twisted yarn process, establish a design technology for ply-twisted yarn, simplify it into one process through lightweight rotating components and yarn path design planning, reduce process energy consumption and production time, avoid yarn loss and yarn twisting back, and improve yarn quality. Among them, process optimization can save energy by up to 10% by eliminating the inverted tube process. The direct drive technology of the plying spindle motor can avoid the kinetic energy loss of the traditional process equipment belt mechanism, and with lightweight design, energy consumption can be reduced by 10%. The equipment occupies more than 30% of the space area of the process equipment due to the use of a composite twisting yarn process technology.