On the basis of principle instructing and characteristic analysis of switching solenoid, its proportional characteristic was studied by an experiment. Probability analysis of experimental results was shown: switching solenoids had stable proportional control interval which was about 1 mm wide. It could be used on the proportional valve with displacement enlarging instead of proportional solenoid. Experimental results of currentforce characteristic show that its linearity is good and the output electromagnetic force is similar, when the output displacement was 1.5 mm and 2.5 mm.