The invention relates to a large bobbin and small bobbin mixed control method. Tension F is set on a human-computer interface and transmitted to a PLC controller, the tension F and yarn linear velocity V obtained through calculation are transmitted to a direct current servo controller through the PLC controller, the measured bobbin revolution number R is transmitted to the direct current servo controller, the revolution number R is the number of bobbin rotating rings in unit time, N is calculated by the direct current servo controller according to formulas: the practical bobbin rotating diameter D=V/(R*pi), and the servo motor output torque N=DF/2, namely N=FV/(2R*pi), and finally the output torque of the direct current servo motor is controlled by the direct current servo controller according to calculation results. By means of the large bobbin and small bobbin mixed control method, the aim that bobbins different in diameter are the same in yarn producing tension is achieved, the aim that the tension is kept constant in the process that the bobbins are gradually reduced is guaranteed, the warp knitting beaming quality is improved, and the production difficulty and the production cost are reduced.