To improve the quality of RGBW liquid crystal display module, based on tested data of RGBW liquid crystal display module and theory analysis, the method to improve RGBW module is proposed. Trough FPGA signal conversion algorithm, we can get the RGBW automotive LCD module with 50% transmittance increased. As the color filter (CF) is changed, the RGBW LCD has some issues, such as crosstalk, color cast and horizontal stripes flashing. By testing different polarity reversal drive corresponding waveform and CF permutation combination, the reasons of the problem is concluded. Results show that the RGBW LCD pixels in the polar line up with the need of the CF match, otherwise will occur crosstalk, color cast and horizontal stripes flashing. Counterparts in the design of LCD module, the polarity of the same color and same line pixels need positive and negative balance, otherwise the display quality of the module will be degraded.