The utility model discloses a vacuum pre -conditioner vacuum degree detection and controlling means for vacuum pre -conditioner's vacuum state control. Including shell, pressure sensor, analog output module, controller, pressure sensor is fixed in inside the vacuum pre -conditioner, analog output module connection pressure sensor, pressure sensor connection director, the controller includes forced induction control module, and forced induction control module connects evacuator, and the pressure negative pressure value feedback of forced induction control module in through vacuum pre -conditioner is controlled vacuum. Suitable pressure sensor is used in this design, has remain original platinum resistance temperature indirect control system simultaneously, and the control picture remains original vacuum meter and shows, increases the negative pressure control model, and the last negative pressure value that increases of HMI shows, make vacuum pre -conditioner have free choice negative pressure and temperature control mode simultaneously and carry out the parameter setting, it is low to have solved detecting element measurement accuracy, and the problem of experience adjustments is leaned on in temperature and pressure 's hysteresis.