A new piezoelectric ceramic linear driving method has been presented in this paperer. The tunable Fabry Perot (F P) cavity is driven by piezoelectric ceramic,thus the wavelength of transmission light through the tunable F-P cavity can be changed.The transmission light wavelength is calibrated by a grating array, so the voltage displacement characteristc curve of the piezoelectric ceramic can be obtained，fitting the inverse function of this curve as a new drive voltage curve，which can drive the piezoelectric ceramic move as a straight line.The movement curve of piezoelectric ceramic driven by this method has been tested by using the tunable F-P cavity，and the result shows that the use of this method to drive the piezoelectric ceramic，the variance of the movement curve and the straight line which shares the start and end point of the movement curve is 393.78，compared with the result of driving by triangular wave voltage which is 44 554.65，the linearity is greatly improved.