In this text we elaborated the mechanism transmission principle and Electricity dominating principle of the liquid packer machine, the PLC programming method, the programming software CX- P 3.1 of function introduction, the principle of touch screen and programming method .In addition, designed through the contents above to hold the PLC control system that controls the liquid packer machine for the signal switch with the touch, carried on a great deal of improvement of the old liquid packer, make its credibility higher, and operate more convenient .Also introduced the method of some exaltations to improve credibility of the PLCs in the spot work environment in the text. In the end ,there are the procedures of PLC’s and touch screen’s, being provided for someone checking or consulting.