The Big-character printer is a dot-matrix print equipment used in industry field. The print head is the key part of it. Sixteen jet valves are arranged in three lines alternated regular framework. Every valve is driven by giant magnetostractive actuator (GMA). The dynamic characters of valve body and GMA have been studied in the paper. The square wave response experiment shows that the valve bandwidth is more than 400Hz. The response plot has a good agreement with the simulation result. Meanwhile, the print dots are clear. Therefore, the BCP based on GMA could fulfill the requirement.