The radial compression force situations of alfalfa have great effect to the energy for compressing process, the manufacture of compressing equipments and the quality of alfalfa products. In order to find out the radial force situations, they were measured by using electric measurement technology under different initial densities and different compressing velocities. The rules of compressing density, initial density and compressing velocity influence on the radial compressing force were found out. At the same time, the alfalfa was relatively easy to curve under axial compressing force and radial compressing force. It is found that these factors are the essentials in the design and application of compressing equipments.