In the field of agriculture, machines are very important tools to increase the productivity of good quality products. Therefore, it is necessary to develop such technological machines, constantly updating the working mechanism. The mower is one of those machines that cutting mechanism is a very important working device, which must been continuously improved. Therefore, a new mower’s double cutter-bar is designing to improve the technological and mechanical performance of the mower. This paper concerns basic parameters of mower’s double cutter-bar mechanism. A kinematic study concerning the double cutter bar mechanism using the method of closed contours, therefore analytical equations are developed, describing the trajectory of the knives, the speed and the acceleration, while also determining the necessary driving power as well as the device power supply and pinch, thus justifying the basic parameters of this mechanism. To validate these mathematical expressions experimentally, a prototype of this mechanism is made within the Kazakh Institute for Scientific Research on Mechanization and Electrification of Agriculture allowing to adjust and improve several design and technology parameters. The correctness of the theoretical premises is confirmed by testing the developed prototype mechanism in agricultural fields.