The invention discloses a multivariable deduction, predication and control method for a middle-speed coal pulverizer. Through an extended Kalman filtering method, the coal output amount of a coal pulverizer is estimated in real time through a pressure difference between an inlet and an outlet of the coal pulverizer and also through the outlet temperature, an estimation value of the coal output amount is taken as new controlled amount to be added to a control system, and the rotating speed of the coal pulverizer is additionally adopted to serve controlled amount. In this way, load instructions of the coal pulverizer can be quickly responded, and the time delay of a pulverizing system side can be shortened. A model prediction control algorithm is employed by the control method. Compared with a conventional PID control method, the multivariable deduction, predication and control method has the advantages that the primary air quantity and the outlet temperature can be better adjusted, and disturbance caused by changes of the quality of coal can be well prevented.