Squeezing device of ore pulp grade instrument and filter cake squeezing method

The invention relates to a squeezing device of an ore pulp grade instrument and a filter cake squeezing method, the squeezing device comprises a lifting structure and a cake pressing structure, the lifting structure comprises an upper cylinder and a frame which is connected with a piston rod of the upper cylinder and is driven by the piston rod of the upper cylinder to move up and down; the cake pressing structure comprises a lower air cylinder, a pressing tank and a pressing plate which is connected with a piston rod of the lower air cylinder and driven by the piston rod of the lower air cylinder to move up and down, the pressing tank is connected to the lower end of the frame and moves up and down along with the frame, and the pressing plate is arranged in the pressing tank in an up-down moving mode. And the pressure tank is used for moving downwards to press the slurry fed into the pressure tank into a filter cake after the pressure tank is pressed onto the filtering part, and moving upwards to demould aft