Aiming at fixed state and free state of the liquid crystal display （LCD） upper substrate, two calculation model are established respectively, and simplified LCD drainage effect basic equations by using MAPLE method. Based on the given initial boundary conditions and through MATLAB calculation programming, the running time was taken as technical specifications to complete the program optimization. For the fixed model of upper substrate, liquid crystal director was gradually turned to the direction of the electric field after adding electric field, when the box thickness was 50 μm, after adding a constant 105 V/m electric field, the maximum velocity of liquid crystal flow that caused by the liquid crystal molecules rotation was 27.5 μm/s, which occurred at 0.23 s after adding electric field. For the free model of upper substrate, when the box thickness was 50 μm, after adding a constant square wave electric field, whose field intensity was 105 V/m, the frequency was 1 Hz, duty ratio was 20%, the cycle was 6 of square wave, the maximum speed of the liquid crystal cell was 259.3840 μm/s. Compared the numerical calculation and experimental data, the size of displacement of the LCD upper substrate in the same magnitude and the motion trace is very consistent.